I'm one of the lucky ones that's gonna be testing SP1 real soon, maybe even this week. I have a legal copy of XP Pro that MS gave me at the end of the XP beta, but on the weekend I decided to do a clean install using the corp files and key. I'll post here to let you know what happens. Personally, I don't expect there to be any kind of lockout. What about using an MSDN key? Not impossible to get...