Nvidia’s Vista drivers have been horrifically slow to mature, especially for what should be their flagship products (8800 series didn’t have SLI support at all until a month and half ago).
I heard the most recent round of NVidia drivers for vista were pretty good as long as you didn’t want to do SLI stuff.
If ATI will not be releasing anything till June, then I guess Ill suck it up and fork out the cash for a 8800 GTX card. I never thought I would ever be someone to spend more then $250 for a video card, but looking at the longer term performance I think it would be a mistake to go with anything less.