From Microsoft Watch: Service Pack 2 (SP2) - due out around mid-2004, according to Microsoft's timetable - will include so many new features that it is practically a new version of Windows. Some Microsoft executives have admitted as much.
Dunno about you, but this may be the second time I don't install a SP right when it comes out (last time was SP4 for Win2000 when it blew up tons of IIS servers at work). So many security enhancements... I'll wait for a day to be able to roll some back as I'm sure they'll affect me as a developer.