The Parallels website now warns that it is not compatible with the Mac Pro:
“At the moment Parallels Desktop doesn’t run on Mac Pro. We’ll provide an updated version that will function on Mac Pro soon. Click here to sign for Parallels news and stay updated about this issue”.
However, they claim there is a patch in development. This is great news. Let’s hope that they can pull it off. If not, this could be a serious blow to Apple’s quest to capture some of the PC crowd with a mac that can run windows.