You still don't get it; Nvidia DOES care about XP and they DO expect their GF100 line to run on XP.
XP is still the OS used by more mainstream gamers than either Vista or Win 7. And you forget that the BULK of Nvidia's sales - GTX 460, GT 450, GT 440, GT 430, GT 420 and GT 410 - The sub-$300 down to $70 video cards - are to the mainstream buyers - not the elitists like you who forget there is more to life than $500 video cards.
The worst thing about the current GeForce drivers is that they ALSO SUCK for Vista and Win 7 - once you get outside the popular games and try to play older games with demanding settings. AMD graphics is miles ahead with their current drivers for XP and for older games.
Apparently, no one likes to hear the truth, do they?
No point in talking about mainstream cards until they come out, whenever that might be.
For the high end, the only cards that NV have managed to release so far, XP doesn't really matter. If XP drivers still suck in however many months there are until they get a real lineup out, then it will be a real issue.
For NV, there is no life for GF100 outside the $400~500 cards. There is no mainstream. As far as all the other games not playing nice in XP or 7/Vista, that is a real problem, but XP support is not (yet) a real issue for the GF100 line.
Also, having an HD4850 which I purchased for around the same price as HD5770's go for these days means I am not particularly an elitist. My max price for a card is the HD5850 level and I prefer to keep it below that.