Hearthpwn

Taunt granters stave off damage in the early game, AoE manages the board in the midgame, and heals ensure that you aren't burned down in the late game.  This is a very solid matchup for this deck.

Save some AoE for when the board is flooded with tokens.  Do whatever you have to, to kill Violet Teacher as soon as it hits the table.  Barring that, drop Loatheb to buy a turn.  If you deal with both Teachers, your opponent will have extreme difficulty busting through your taunts.  Many of their cards have low utility in the late game and you should be able to outlast them.

I don't remember what happened in the game I lost, but it must have been anomalous, because this is an extremely favorable matchup.  Play agressively to put as much early damage on as you can, so that you can finish with Savage Roar.  Hold a Keeper of the Grove or a Poison Seeds for when your opponent drops Doomsayer.  Save all heals and Loatheb until after Alexstrasza is dropped (this includes Ancient of Lore).  Generally, the Mage won't have enough damage to outpace your healing.

The early and midgame are about jockying for board control, but you have plenty of good tempo plays and removal to keep up.  Focus on keeping their board as clear as possible and try to save some removal for when a Flametongue Totem or a Mana Tide Totem gets hidden behind a taunt.  Beware the Al'Akir the Windlord and Doomhammer finishes with Rockbiter Weapons.  Keep trading and you should be able to outlast them, because of Shaman's deficient card draw.

I'm a little surprised this matchup went so well, because the taunts make it difficult to finish the game out, and Ramp should definitely be stronger in the late game, but I suppose Ramp has some difficulty if it falls behind in board control early.  Try to save an answer for Ancient of War, be it Keeper of the Grove, The Black Knight, or worst case, Poison Seeds.  Also, make sure your board isn't too "Swipable", and if it is play Loatheb.  Beware the opponent's Force of Nature + Savage Roar finisher, especially if they are playing the faster version.  Use heals to move out of range as necessary.

The (former?) king of the ladder is a fairly good matchup for this deck.  Be aggressive, but getting one early taunt down is good to make sure you don't do any unnecessary bleeding.  Always use charge form of Druid of the Claw, because this matchup is a bit of a race; Miracle Rogue usually has no difficulty removing targets regardless of health; and it is more resistant to Sap.  Keep track of how much Leeroy Jenkins damage the opponent is capable of doing on the next turn, and heal as necessary.  Loatheb is amazing in this matchup and should be saved for just after a stealthed Gadgetzan Auctioneer is played or as you are anticipating a burst combo.  Poison Seeds also shines, and should mostly be used to destroy stealthed minions (more often I find that I am destroying a large Edwin VanCleef and/or Cold Blood buffed minion than a Gadgetzan Auctioneer).

This ever popular deck, is now even more popular with a boost from Nerubian Egg, Haunted Creeper, and a general anti-burst movement.  Luckily this deck has a lot of tools to combat zoo.  Early taunt granting soaks up a lot of enemy minions and are decent tempo plays.  Usually you are just trying to keep a foothold on the board until the midgame where you can use an AoE spell to clear the board.  Try to hold off on your AoE as long as you reasonably can.  Once you clear the board in the midgame it's usually smooth sailing.  Keep making trades, but try to keep as many minions as you can on the board.  Zoo often has trouble finishing them off, and you can use them with Savage Roar to end it.  The copious card draw in the deck helps you keep up with Life Tap.

As is usually the case for me, my "other" winrate is below my average.  It's difficult to make the right plays when you're not too familiar with what you're facing.  In this category were some Priests, Control Paladins, Control Warriors, a Secret Mage, a Midrange Voidrattle Warlock, a Backspace Rogue, and a Midrange Warrior.  Control Warrior in particular seemed very tough (Edit: Other people are telling me this is going well for them...so maybe it's actually pretty good, and I just got unlucky).

I didn't feel that my deck was too weak in this matchup, and I'd say it's probably closer to a 50/50 thing.  There seem to be two problems: Starving Buzzard + Unleash the Hounds is a potent combo, since you will usually want at least 3 minions on the board; and Hunter can easily do damage through your taunts.  Try to keep your board compact, and look to trade where possible, maintaining as much taunt as you can.  Think carefully about whether it is worth triggering an opponent's trap this turn, especially if Eaglehorn Bow is out.  It may be better to develop your board another turn to set up Savage Roar or heal.  Ancient of Lore is often better as a heal, since games are relatively short and Hunter can do a lot of damage early.

The nightmare matchup.  I saw very little Handlock until rank 1, and if I had continued there for much longer I would've tried to find room for a Big Game Hunter.  Keeper of the Grove is decently good at removing Twilight Drakes, but the removal in this deck is not quite strong enough to deal with Mountain Giants consistently.  Handlock also has a number of strong board clears that keep you from flooding the board, which you often want to do.  The burst potential in this deck is not quite as consistent as Fast Druids or Token Druids and so it can be difficult to keep the Handlock's health at a point where Molten Giants are manageable, but you are still within lethal range.  Force of Nature and Savage Roar are almost necessary for pulling this off.  Your minions aren't as beefy as Ramp Druid's so you'll have a harder time busting through their giant taunts.  All told, a rough matchup, but still winnable.

A card capable of establishing its own archetype.  Watcher Druids have fallen out of fashion lately, but I can still remember when they were hugely popular in season 1.  I think that Naxxramas has breathed new life into it though adding versatility to the Watcher combos with Nerubian Egg.  Ancient Watcher derives its value from having a two mana discount on the Chillwind Yeti, a card that is already quite strong and prevalent in the meta.  The key is to "activate" (silence or taunt) the Watcher cheaply to maintain the tempo advantage.

The new Naxxramas card that inspired the deck.  Much like the Ancient Watcher, this card needs to be "activated", in this case, destroyed.  It works best when you force your opponent to spend resources to destroy it, either by having it die to area of effect or by giving it taunt, but destroying the Egg yourself can still be lucrative.  Because of the numerous ways to give the Egg attack or taunt, the 0/2 body is possibly a benefit rather than a detriment to the 4/4 that you are getting for 2 mana.

Probably the best activator.  Works with both Watchers and Eggs, and even enables the Eggs to attack.  Don't get overzealous trying to break the Eggs though, it's usually better to force your opponent to do it, unless you have reason to think your opponent is holding a silence (or is a Priest...because they are really good at stealing Eggs).  You should almost never play this on an empty board.

Cheapest activator.  Great for a turn two or three taunt, which can be very useful against aggro.  Still pretty good value on an empty board, and is frequently a turn 2 play even if there is nothing you want to give taunt to.

Keepers can activate watchers by silencing them.  They are your only silences in the deck though, so if you know your opponent is going to play something that needs to be silenced, e.g. Tirion, hold onto it for that and try to activate your Ancient Watchers another way.  The deal 2 damage can still be very useful especially against aggro where it can kill a Knife Juggler or Dire Wolf Alpha.  You really shouldn't use it to destroy your own Eggs, but silencing your opponents' Egg is a great play.

Savage Roar is a critical part of your finisher, but there are two, and it is often useful to activate your Egg by giving it two attack and trading it into an enemy minion.  You should be looking to get more value out of Savage Roar than just activating an Egg.  Giving your other minions attack should let them trade up or move your opponent into lethal range.

Poison Seeds:  One of three new Naxx cards in this deck.  This card is strange, situational, and debatable, but it has plenty of utility.  Depending on the meta, consider replacing this card with Big Game Hunter, but right now I'm not seeing many 7+ attack minions.  This card activates your Eggs by turning them into a 4/4 and 2/2.  By itself this isn't worth 4 mana, but depending on what else is going on on the table, this can be good value.  It can also turn your unactivated Watchers into 2/2 tokens, which obviously isn't ideal, but it is something to keep in mind.  Generally speaking, against control decks, Poison Seeds acts like removal on a couple of difficult to deal with enemy targets, turning them into something more manageable.  The downside is that your opponent gets to attack with the Treants first, giving your opponent tempo.  There are some potential board clear combos (with Starfall or Bloodmage Thalnos + Swipe), but they are too expensive to be very exciting.  I've found that Poison Seeds is most helpful against Miracle Rogue to kill stealthed minions, and against Freeze Mage to keep a board presence when faced with Doomsayer.  I'm not completely sold on this card, but it's done enough to earn a place so far.

One of the best cards in the game.  The card draw attached to a formidable 5/5 body is a turn 7 game changer.  The heal is very useful in some matchups as well.  Be aware of your opponents' potential finishing combos, and use the heal when it is necessary to move out of range; otherwise, go for the card draw.  Hold on to them against Freeze Mage, and use them for heal after they play Alexstrasza.

A versatile removal option.  Against aggro, usually the 3 damage option is better to remove minions with dangerous effects hidden behind taunts, e.g. Knife Juggler and Dire Wolf Alpha.  In other matchups, the use depends on circumstance.  Try to think a turn or two ahead, and if you think your hand size/quality is going to lead to a very weak turn, look for a way to use the 1 damage option; otherwise, feel free to take the 3 damage option when a good opportunity arises.

Solid card in a suddenly crowded 5 slot.  The spell power tremendously improves your AoE (Starfall and Swipe), but the 4/4 body is usually good enough to play without the combo.  Opponents go to great lengths to kill it right away, so it is also good for dictating the pace of the game.

Look to combo this with your AoE, but it can also be good to bump up the damage on Wrath.  If your hand quality or size is getting low, it also makes sense to drop this on an empty board.  Your opponent will probably have to kill it for fear of a game changing Swipe.

Against midrange and control, this often acts like a four damage removal spell with some upside, but against aggro it really shines.  It kills one dangerous target and will probably kill one or two more, or facilitate more favorable trades.  This is especially true against Shockadin, Face Hunter, and Zoo.  The first two because of their plethora of 1 health minions, and the last because Zoo often leaves its minions at 1 health when clearing your board.

Generally considered to be weaker than its brother Swipe, and hence a one of, but in some matchups it is the stronger of the two.  Shaman comes to mind, as the AoE option will clear out the totems while damaging enemy minions.  The five damage option is great for killing Sen'jin Shieldmastas, Ancient of Lores, Chillwind Yetis, and others.

This card combined with Savage Roar gives you a 14 damage finisher from an empty board that scales proportionally with the size of your board.  This combo is your primary weapon for closing out stalled games.  With the combo in hand, look for ways to sneak extra damage in on the enemy hero until he or she is in range.  The abundance of sticky minions in this deck makes it easy to get extra value from your board.  It is very tempting to add a second copy of this card...

Early game this gives another 3 drop in case you don't have Harvest Golem to establish board control.  Early board presence also makes it more likely that you'll be able to find heal targets on the board than in some other decks.  Later in the game, this card fulfills its anti-burst role.  Always tabulate your opponents' potential damage taking into account the standard finishing combos.  When you're in the danger zone, use this to sneak out.  Many decks will cede board control when setting up a burst combo, so an extra turn could totally turn the tide of the game.  If you are facing Handlocks frequently, I recommend switching this card to Big Game Hunter.

Since this only came out a couple days ago, I haven't had a lot of time to play with it yet, but it seems like an excellent addition to this (and most) decks.  For comparison's sake, I used to run a second Azure Drake in this slot.  I primarily use it to block finishing combos and board clears.  Occasionally you should get this feeling of impending doom: perhaps you have a large board with a bunch of one health minions against a druid; or maybe your opponent just played Alexstrasza or stealthed a Gadgetzan Auctioneer.  Play this card to buy a turn.  These are game deciding situations and often one extra turn can change the victor.  If the opponent has almost no board presence, this is a good card to play to set up a Savage Roar finish on the following turn.  They will have difficulty removing your minions, adding to the value of Savage Roar.

Because of Druid's versatility, many of the removal options have already been discussed: Keeper of the Grove, Wrath, Swipe, and Starfall, but some minions you will face are just too tough for these to be effective.  Druid has no endemic, single target, hard removal, but there are some situational options.  Poison Seeds is one, but is generally bad against taunts, because you forfeit your minions' attacks by morphing them into Treants.  Enter TBK.  Non-aggro, non-Miracle decks are forced to play taunts to survive against decks like Zoo and block finishing combos from Combo Druid, Miracle Rogue, Handlock, and others, so there is generally no shortage of targets.  It is a total game changer when it hits a large target, like Sunwalker, a taunted giant, Ancient of War, or Druid of the Claw, but almost any taunt you can kill will give you good value.  If there is no other play, TBK is also decent on an empty board.  6 mana is expensive, but a 4/5 is still pretty hard to kill.

The classic value 3 drop.  It's a sticky card, which is good with buffs like Defender of Argus or Savage Roar.  Often it will sit behind a taunted star, chipping away at the enemy hero, slowly moving them into lethal range.

Incredibly versatile and full of value.  Taunt mode is often better because of the additional health, but more so than in some other decks Charge mode is used.  In charged mode it can safely sit behind your other taunts and quickly lower your enemies health into range.  It also makes you less vulnerable to The Black Knight, which can often decide Druid vs. Druid matches.  You should almost always choose charge against Miracle, since it is somewhat of a race, and they can usually effortlessly deal with your minion regardless of health (Sap comes to mind).  Consider charge mode + Savage Roar as a finishing combo.  I spent a lot of time talking about charge mode, but taunt is still very good in a lot of cases.  It may be 50/50.