http://us.battle.net/hearthstone/en/
A TCG based on Warcraft, Heroes of Warcraft (HoW?), that will be for PC, Mac and iPad. I'm not that big into the TCG style games, but I'm interested to see what a very small team inside of Blizzard has done in a short time. I think I'm more interested in that angle, Blizzard doing a quick and dirty development process, than the game maybe but it does kinda look cool too.
-Fulbert