As of Tuesday April 12th XP users will no longer be able to block SP2 so if your running an XP box and don't want SP2, get ready to have it forced upon you becuase Microsoft are giving you no say in the matter!
Here is what Microsoft have to say on the matter:
Because of these significant improvements, Microsoft views Windows XP SP2 as an essential security update and is therefore distributing it as a "critical update" via Windows Update (WU) and the Automatic Updates (AU) delivery mechanism in Windows. Microsoft strongly urges customers with Windows XP and Windows XP Service Pack 1-based systems to update to Windows XP SP2 as soon as possible?
Personally I think this out of order, many people I have spoken too do not wish to use SP2 for various reasons.
Source OSnews.com
IT Observer