This Broadband Reports forum is running a Windows XP SP2 upgrade war story thread. Might be useful.

Also you can opt out of the upgrade (whilst retaining your Automatic Upgrade facility in XP) for the next 4 months by visiting this link at Microsoft. Follow the instructions (i.e. Open the download rather than Save it) and bingo, no SP2 until December. I’m not sure I want it at anytime, but we’ll see.