When you encounter a compatibility warning, you're redirected to a help topic for more information.
On my Windows 8 Pro x64 RTM, downloaded from MSDN and installed as an in-place upgrade on Windows 7 Ultimate x64, the compatibility help shows
You're using a prerelease version of Windows 8.
when you expand the "What version of Windows as I using?" link.
Is this normal and expected behavior (something that Microsoft neglected to update during the release cycle) or is there something wrong with my install?