Hearthpwn

I've ranked from 20 to 9 so far using this deck, hopefully it might help some of you.

Main Combo & Focus

Against aggro, clear the minions using Devolve & Mealstorm or Lightning Storm and heal using Jinyu Waterspeaker. Once they run out of cards, put board pressure with Jade Golem cards, Doppelgangster + Evolve combo. Don't be afraid to evolve your Jade Golems once they hit 5+. The outcome is generally always positive.

Against control, your Jade Golems are unstoppable and you can build them up with the Jade Golemn cards pretty easily. When your opponent has used their board clears, you can retake the board pretty easily using Brann Bronzebeard and the Jade Golemn cards. Evolve just makes it even better.

Strategy & Mulligan

Warrior

Since you will find mostly pirate warriors in the current meta, mulligan for Devolve, Mealstorm, Jinyu Waterspeaker.

Against control, it is better to keep Jade Spirit, Jade Claw, Mana Tide Totem or Doppelgangster for that turn 5/6 evolve. Generally against control you want to focus on building up your Jade Golems.

Shaman

Most shamans are face shaman or aggro shaman and thus should mulligan for card]Devolve[/card], Mealstorm, Jinyu Waterspeaker.

Druid

Focus on building up your Jade Golems. Usually you want to stay ahead of the Jade Druid by which is quite easy since you have your evolve mechanic. Just make sure you have a removal for their possible early turn Fandral Staghelm & Brann Bronzebeard. Jade Lightning should always be kept (1 copy) during the mulligan.

Priest

For Renopriest, you have to bait out their only board clear - Dragonfire Potion. Once you do that, it's pretty easy to maintain control of the board by focusing on building your Jade Golems with a Jade Golemn card and Brann Bronzebeard.

For dragon priest or inner fire priest, keep a copy of devolve so once they buff their minions, you can immediately counter that by using Devolve.

Rogue

Similar to aggro warrior. Keep Devolve to remove their buffed up concealed minion. 

Warlock

Renolock is difficult to beat in general but you can if you manage to make him use up Twisting Nether and Shadowflame. Even if they play Reno Jackson after that, you can use Bran + Jade Shieftain to prevent their final burst and retake control of the board. However, this is still going to be a difficult match up.

Mage

Keep constant pressure and this should be possible to win.

Palladin 

For anyfin palladin Devolve those warleaders, or Hex them and they can't do much after. Similiar strategy for Buffadin.

Hunter

New class, will update once they appear on ladder.