Oh yes, I forgot. Zune is also incompatible with Windows Media Player.
You know, the player Microsoft has been trying to make the singular focus of its entire operating system (and probably the Media Center edition, too? I've never used Media Center before).

No sir, as a Zune user you have no choice but to export all your music outside of that centralized player and into the special Zune player if you want to use it (it increasingly seems like "special" in this case really means "special" as in "this one rides the little yellow bus every day" or as in "handicapped orphan". )