Didn't see this mentioned anywhere, but it's semi interesting -- some notes from a recent MS presentation regarding their development of the 360 dashboard GUI. A few tidbits, as well as a look at some of the other interfaces MS was considering (eww!):
Full article:
http://experienceucd.com/index.php?option=com_content&task=view&id=20&Itemid=48
Full article:
http://experienceucd.com/index.php?option=com_content&task=view&id=20&Itemid=48