I love it when you guys go at it!
Look, the truth is that BF3 can easily use more than 1GB of VRAM - I've seen it happen at 1920/ultra in multiplayer, not just at 2560 as today's reviews would have you believe. I actually ended up using 600MB of system memory in addition to the 1GB of VRAM at one point (I'm not saying you can just add those up to total 1.7GB used, but obviously it was over 1GB). It's a showstopper if those are the settings you want to play at. But the other half of the story is that most cards can't push that anyway.
@Toyota - I agree that at any settings the 570 can actually push, the 1.25GB of VRAM is not the limitation. That being said, I wouldn't necessarily call the 570 optimal, as it's on a razor's edge (I'm betting the game is using 1.2GB at those settings), and in some scenes, it could exceed the limit. Nothing wrong with the 570 generally, but I think 1.5-2.0GB cards are a safer bet. Until AMD fixes its MSAA performance, however, that pretty much leaves us with the overpriced 580 and the slightly unbalanced and overpriced 560Ti 2GB.