New motion controller
Kotaku - Microsoft Makes You The Motion Controller With Project Natal - Project Natal
Live! getting Last.FM streaming radio
Kotaku - Last.FM Coming To Xbox Live - Last.fm
Live! getting Facebook and Twitter integration
Gizmodo - Facebook and Twitter Come to Xbox Live This Fall - E3
Live! Netflix getting the ability to add straight from the interface and the video store is being renamed the Zune store and getting 1080P streaming.
Gizmodo - Netflix Lets You Add to Queue on Xbox, Video Store Gets 1080p - Xbox 360
These are some great upgrades to the Live! service.