I did the upgrade not a clean install. I was hoping to try the out of beta BootCamp so I tried it last night.
I tell people to read manual first for everything they do but I don't follow my own instruction. I should have read the manual first.
I tried that with my genuine OEM version of XP Pro which isn't SP2. BootCamp doesn't allow that but I went ahead regardless. It wasn't OK.
That forced me to reinstall OSX which I found to be better. After the upgrade the startup screen changed, the Apple logo has gone and for some reasons the boot up took longer (I didn't time it with stop watch).
The Apple logo returns during boot up after the clean install with the revolving wheel which I prefer. A clean install also has the new Safari.
I may try installing XP again but I think it'll be hard to buy XP Pro with SP2 now from shops!
PS: the fastest Vista notebook ever is a Mac