They just released a huge amount of cards on their facebook page. I assume they're also on hearthpwn. One takes control of an enemy secret, another Stoneskin Gargoyle a la mech variation, Legendary that Battecry: destroys an enemy Beast. Lots of cool stuff
Hearthpwn link:
http://www.hearthpwn.com/ (just scroll down)
Tons of new cards here.
Tree of Life seems like it could see decks built around it. It basically resets everyone's life total. Kindof an anti aggro card, but it costs 9 mana and your turn. Really interesting though.
Hobgoblin seems like it could be good in a Weenie or Token deck (3 mana, 2/3 +2/+2 for every minion you summon with 1 attack).
Kezan Mystic seems like a really cool anti-secret card (4 mana 4/3 steal a secret).
Wee Spellstopper seems like it might potentially make viable all those big minions that do nothing the turn the come out (4 mana 2/5 prevent adjacent minions from being targeted), but it costs so much that maybe not.
One Eyed Cheat seems like a poor attempt at making Pirates a viable tribe (2 mana, 4/1, rogue card, pirate that gains stealth whenever you summon a pirate).
Shadowboxer looks strong, like a Knife Juggler just for priests.
Floating watcher looks cool. 5 mana 4/4 Warlock card that gets +2/+2 every time you take damage. Tap to victory! A little slow, but potentially something that could make a different sort of Warlock deck viable.
Cogmaster's Wrench seems crucial to every Mech deck that can run it. (Is that a Paladin card? I'm not sure). 3 mana 1 attack weapon that has +2 attack when you control a mech.
Grove Tender seems strong in Druid Ramp decks (3 mana druid card, 2/4 choose one: each player draws a card or each player gains a mana crystal.)
Crush seems like a strong change to Warrior. New removal spells are always big. 7 mana, destroy a minion if you have a damaged minion it costs 3 mana.
ALSO 3 balance changes were announced:
Soulfire now costs 1. FUCK YOU ZOO. (probably still worth playing.)
Gadgetzan now costs 6. FUCK YOU MIRACLE. (This seems like a huge nerf to miracle.)
Flare now costs 2. FUCK YOU HUNTER. (I think Hunter will still be strong, but running Flare will be a harder choice now.)