I've been using XP for about 3 months. I used the trial version.
I wouldn't be so sure about the Win 2k to XP thing. It seems logical at forst to assume that if it works in Win 2k it should work in XP. Be prepared for a bit of a surprise, a fair amount of stuff doesn't. Cubase users are struggling at the moment because it isnt easy to get working properly on XP and people are coming up with all manner of varied solutions. It's about time Stienberg pulled the finger out and make an official comment really...
As for the hardware thing, XP ships with drivers for almost every contingency. If your hardware doesnt have an official driver yet Microsoft seem to have made one for almost all of the most common components. You are probably right to waiut though...
the wheels of progress... they turn slowly....