Hearthpwn

I am 54-34 with this deck 

v Hunter 4-0, v Pally 5-8, v Warlock 9-10, v Rogue 9-3, v Shaman 1-1, v Priest 1-3, v Druid 6-3, v Mage 2-2

Strengths 

Massive Heals! Tons of Taunts! Huge Burst Potential from Windfury plus Buffs! A Potentially Devastatingly Powerful Single Drop in Shudderwock!

Great against Aggro! (All Paladins, Odd Rogue, Baku Hunter, Tempo Mage, etc, etc) Does require some heads up plays, but your taunts and heals can keep you alive enough to set up a massive board state and smash them down. 

Good against Hunters of all shapes and sizes. These decks just have the board clears to keep you down. The slower ones get smashed by your Windfury plus buffs. Really any deck gets smashed by that but some are more likely to pull removal on it than others.

Can be decent against Spitefulls. You do need a bit of luck to take down the big minions you pull. You are honestly hoping to not HAVE to Hex them. It is way better to stall with Glacial Shard and trade them down with a Flame Tongue. 

Weaknesses

Warlock and Pally are hard match ups, but they are tier 1 so what can you expect. I am definitely at the stage of refinement of trying to get these match ups decent. The problem is that most techs for one hurt you against the other. I feel like my Warlock match up is way harder so I have teched pretty much all in for that match up. There is definitely an argument, especially if you see a lot more Pallys that you just concede that Warlock will be unfavored until they nerf it, and they will for sure, and in this case I assume you cut Hex one, or two for Lightning Storm. You possibly cut Zola, tho I am starting to think I seriously underrated that card. Its synergy with Shudderwock is rare and inconsistent as far as the infinite Shudderwock dream, but 3 2/2 draw* a card you want is not bad in this deck. Shudderwock generating another copy of something you may want on play is good too even if it is not Shudderwock. 

Consistency is also a weakness because you can draw the cards that give you Windfury or Lifesteal too early. This honestly hasn't been that big of an issue because you really face a situation where you need full value for these cards to feel powerful. 

Update
Not sure cutting Zola the Gorgan was the right call. I just literally had it never get me a second Shudderwock. Even when Shudderwock copied himself twice it still went out of order, and in the ONE matchup where I actually need multiple Shudderwocks. 

Im just mad at the card but I think you may NEED it in the Cubelock matchup, and need it to work. I am 4-9 in that match up and the games I win feel like literally everything went my way. I opened with double Hex, I hit the weapon with removal, I nail good stuff with MTC (It is actually pretty easy to get good stuff here, actually I think this card is champ in this meta and prolly why Spiteful Druid has such a high WR) 

I caved in and ran a Mana Tide, most the changes were to make the deck more consistent across the board. More redundancy on the Corpsetaker effect, and a smoother curve. It has helped a lot with gassing.