Well I didnt upgrade. I decided not to because I felt there was no need for me to since XP was "perfect" for my uses. Also Im glad I didnt upgrade to Vista because now seeing all the bad things that came of it It would have been a waste of money in my personal opinion.
I am not moving to Vista as I find it is memory and resources hungry. I have switch Vista to XP for many friends as they find the interface less friendly and most important is slow when you start to install more applications
The only thing I really like about vista is DX10. I built a new gaming rig and for DX10 I got vista. other than that, I never upgraded any of my other machines.