Cesar over at ZuneInsider tried to use the Zune remote with his Xbox. And it comes out they are compatible with each other. Watch a small presentation by Cesar: Zune Wireless Remote Works with Xbox 360
ZuneGuy (Bill Witress) wrote: Actually, many different remotes will control the Zune/360. Anything based on the Philips RC6 standard should work. What does that mean? Well, for starters, if you have any “universal” remote sitting around, it is likely to be programmable to control both units. Just to remind you the Zune remote needs the dock to work with Zune and both of these two are sold separately.
Microsoft, Zune, Xbox, Remotes