If you want a PC now (and I wouldn't blame you, waiting is no fun) then just make sure you get a card with lots of vram.
I read a study on BF3 the other day and on ultra with 4xFSAA it used over 1500mb of vram.
And, that leaves benchmarks etc worthless, because it does not dictate what is actually happening in a game.
GTX 470 755 linked I had. And I had to sell it and buy a 6970L 2gb in order to get BF3 to what I would consider a playable state. It was, to all intents and purposes, unplayable on a 470. It will also be unplayable at that res on a card with a lack of vram. As textures load (looking around you etc) it will pause. It's really, really annoying man.
Thankfully though the engines are all out now. Nothing new (gaming engine wise) is on the horizon so at least I feel kind of safe for now. There's a new Dirt game coming out, but that uses EGO II it seems, so no worries there