Ok, so I finally made up my mind, after getting feedback that apps like the Zune Software, Live Mesh, and VMWare Workstation seem to work under the Windows 7 beta, and went for an upgrade from my main Vista laptop.
The upgrade process did a strange change to my files: it moved them from C:\Users\jota.CREATE to C:\Users\jota. As you can guess, this caused several problems, with Outlook 2007, Zune, Mesh, and others. Mesh especially was especially troublesome, because it started sync'ing files back to the original location, thus doubling the files. I had to manually move the folders, one by one, and this was not a good experience.
VMWare Workstation 6.5 worked fine, if ran as an administrator.
Overal, I must say this has been a great experience until now. Things work correctly, no major issues (I do have occasional intermittent wireless network losses, but I can't pin it down yet to Win7), it doesn't look like a beta. The only thing I don't really like is the default display in Windows Explorer. I much prefered it to open in the My Documents folder, not the library list. I'm pleased, anyway.