Today's update to Xbox Live changes the look of the basic interface with a new font and a blindingly white background in the quicklaunch menu. The basic interface gets rid of that funky carousel look like you're paging through panels on a jukebox, or interfacing something by Apple. Now it's just simple side-by-side windows. It also finally adds a search feature to Netflix, which evens out the main advantage of using a PS3 for your Netflix needs. Improved voice chat voodoo will supposedly make it easier to talk to people.
And, of course, the Xbox interface is getting Kinectified. This is partly accomplished by making avatars less stubby and midgitish and giant-headed, which will make it easier to relate your own flailing limbs to your avatar's. I'm not sure it's entirely successful at normalizing the avatars, because now my already freakish avatar looks like he's grown from a child to a gangly adolescent. I find him even more disturbing.
My favorite change, however, is the ability to forcibly sign into a profile even if it's already signed in with another controller. This will make local multiplayer in general and Rock Banding in specific a lot more convenient.