Sure, I'll bet...during the installation process, it gave me the option:
- upgrade
- clean install
You can do a clean install on a system that you would normally upgrade. The whole "upgrade" process is to ensure that someone purchasing the Home Premium package is an existing XP SP2 Home or MCE, or Windows Vista Home Basic user.
Right now, I've got Home Premium installed and could easily perform a "clean install" over it if there are bugs. So far, there are not, so I don't anticipate it.
Thanks for your concern though