I heard somebody say SP2 installs a virus that sends your name and adress to microsoft when your XP isn't legalRumor spread so fast these days
.
The service pack betas did crash a lot of PC's but hey, that's were beta's are for. The final version supposed to be smooth. If you don't want to take much risk then wait until the 25th and see what it does to other ones PC. But you don't really have much to worry about.
However, SP2 does
refuse to install on some (a lot?) of illegal version. To be excact, it blocks certain groups of XP CDkey's if you have susch a key used on your PC it won't work. You can however change your XP key to one that does work but i won't talk about that any further because of the no-warez-policy here.