The more I read on the "new" AMD cards, the more I despair. We've already seen an 8gb 290X in action, Tom reviewed the XFX DD version, and we already know that in any situation that requires 8gb of vram the card doesn't have the horsepower needed to generate playable framerates.
I think the answer is clear - if anyone has been holding off buying a 2XX card in case the 3XX cards were bigger/better/faster/more, now is the time to buy that 2XX card. Especially as prices should now drop considerably.
And if anyone has been holding fire on an Nvidia card to see what AMD has up their sleeves, the answer is absolutely nothing. Buy Nvidia.