Like others said, just wait.
Actually, the best thing to do is wait until there is a game that actually requires this amount of power. I'm sure you have managed to play through crysis with good details on your 3870 x2, so unless you're a big fan of crysis multiplayer I don't think you should buy anything for a while yet. Even with Age of Conan's requirements it might still be worth waiting for price reductions and more user reviews.
New graphics cards really have a lot going for them in terms of technology but there really isn't that many games out right now that take advantage of super high end hardware. Until we see titles like Stalker: Clear Sky and Fallout 3 that might actually put a larger demand on gpu power it might be worth waiting for a price drop if nothing else.
I'm running 8800 GT SLI and I really think that the only title putting my config through its paces is Crysis and even that is more than playable really.
edit: one small note, if you're running an a super large display than a g200 nvidia or 4800 series ATI config of some kind might really be worth it, but we'll have to wait and see yet.