Oh yes, the hilarity continues.

You can't even use the Zune on Vista (not until a patch comes out in January, which is a long time considering the Vista betas have been around for quite some time).

And by the way, the Zune can't be used on anything less than XP either. No 2000 or anything.

It does not play music tracks purchased at the Microsoft Store. The latter is being shut down and Microsoft is launching a "Zune" store (similar to the iTunes store). Even so, the incompatibility means everyone who bought a large number of tracks from the old store and now purchases a Zune is kinda being screwed.