If you want a heads-up on what SP2 will have in it then take a look here. It looks like Microsoft is trying to make a change at making their code a little bit safer. They don’t look like they are doing a knee jerk response (like in Outlook attachments) but this looks more thought out.
MSDN: developer view of Windows XP Service Pack 2. Beta coming soon.
[The Scobleizer Weblog]