Don't I know it.
To be serious I've been fairly happy with Windows2000 and later with XP.
When you turn all the unnecessary things from XP, it's like w2k with a couple extras added. Meaning it's quite nice.
I still get nausea when I have to use a standard XP installation on my clients.
I don't think so Mickey. There wouldn't be any point to do so. Reversely the 64-bit cpu's benefit a lot from it potentially, especially in memory consuming tasks such as rendering video.