EA's card-based real-time strategy PC game BattleForge is set loose next week, and this action trailer demonstrates some of the powerful forces that shall be unleashed.
I've actually had some time to tool around in the beta for BattleForge recently, and I have to say they've executed the fusion of cards and real time strategy quite nicely. The only problem with it at this point is you really have to purchase new cards if you've any hope of getting anywhere against opponents who've invested heavily into bolstering their forces.
I'd highly suggest heading over to the website and trying out the open beta, see if the game is for you. I'm still on thee fence. My heart says yes, but my wallet screams no.