The 7950GX2 looks to be a great card, but I am thinking about waiting for the next round of Nvidia cards. I'm guessing DX10 will be compatible with the G80 series.
Any word on when G80 cards become available? Also, I'm thinking the second generation of DX10 cards might be a better choice, as to allow some time to work out the kinks with DX10 and Vista.
I hear ATI has some great cards coming as well.
Forget about Vista.
Get a 7900GT or 1900* and they will give you all the human eye can see.
If you really want you can wait....for a long time....and spend alot more and not notice.