Nothing spectacular, but Cesar from Zune Insider found out that the little remote that comes with the Zune AV pack works on the Xbox 360 if you enable inputs from other remotes. Don't believe us? Check out the video.
Nothing breathtaking, but it saves you from having to buy a separate remote if you've already got a Zune with an A/V Pack. Jebus knows we've got enough remotes already.
Use Your Zune Wireless Remote to Control Your Xbox 360 [Zune Insider]