Hearthpwn

Early greed + surprises vs slow openers: 
Young Dragonhawk+Razormaw@3ATK 
Duskboar+Razormaw@windfury
King Mukla to make warlocks mill a card

Midgame
Keep introducing threats as you move to your Spiteful Summoner turn.
Don't be afraid to play Leeroy Jenkins >face for tempo on T5 because we have many ways to finish our opponent from hand, so that means it's usually most important to just apply maximum pressure.

Use your tech toolkit in an optimal way for the matchup.
Example: Weapon removal + King Mukla can burn a Kingsbane. Vs Mage, silence your frozen big minion to keep pushing face. Dragonslayer finds targets in Cobalt Scalebane, not just in dragon priest's pesky Operatives.

Oakheart's Tundra Rhino package= 6-11dmg (+poisonous/token trading options)
1-ATK minions can have 1,2 or 3 damage output on their own (kindly grandma).
3-ATK minions have 3 or 6 damage output, thanks to vicious fledgling (remember infested wolf's spiders also get charge, if you need to make a trade instead of going all face) 

Spiteful Summoner drops:
BAD: 2/4, 3/3, 4/4,
MEH: 3/15, Hadronox, Malygos, 5/8
GOOD: 4/12Taunt, 5/5Taunt, 5/9Taunt(beast), Voidlord
GREAT: 7/9. 8/8. 8/8, 9/7, 9/9, Obsidian Statue
CRAZY: Nozdormu, Mayor Noggenfogger
GAME-WINNING: Ysera, King Krush

Matchups:
I have played 40-something games with variations of this list and I'm happy with my results. 
I have won against cubelock, secret mage and aggro paladin, but I'd say this came through "an intimate understanding of the role of every card in the matchup", rather than this being the new meta-breaking/defining list.
I never lost to combo dragon priest, spiteful priest, shaman or zoolock, but that's nowhere near enough data to say what this is good/bad against. I can only say I enjoy playing it. )

Modifications:
I have tried many variations, following these strict rules: 
-Only 2-ATK minions are the Tundra Rhinos. 
-1ATK and 3ATK minions can only be Beasts.  (hence, no corpsetaker)
-Beasts should be in the majority, because of Rhino synergy.

Replacements:
Harrison Jones - safe replacement, I just don't have him.
Rexxar DK - doesn't necessarily help our face plan. Haven't experimented w him.
Bittertide Hydra - very bad vs Defile, silver hand's, frostbolt+pings...
The Beast - might not be that bad, will have to try.