Bob, have you noticed few changes in Windows booting screen ? Process bar (animated gif) right below Windows logo became blue now. It was green before (green in Home Edition and it was always blue in Professional). Windows version logo is changed as well... there is no "Home Edition" wording any more. Same situation with Professional version... it just states " Windows XP"... no more Home Edition or Professional logo. Of course, inner difference in those two OS'es stays untouched.
Cheers !