Design firm Grid/plane worked with Microsoft on early design ideas for the New Xbox Experience. While the NXE we ended up with is a different beast, it's interesting looking at what could have been.
While Grid/plane's ideas obviously centred around a new menu system, they also "dreamt up an immersive 3D environment for users to explore the latest games, events and online activity within the XBOX Live community". Sounds familiar...
Anyway, if you're interested in checking out an alternate history, one where the "new" Xbox experience looks a lot like the "old" one, only with avatars, hit the link below.