Soxnintendo is the only one this year who wont be livestreaming from there own products.
So Microsoft should be seeing these in no given order
Halo 4
Forza : Horizon
Fable The Journey
Twisted Pixels new game
The new Gears of war
Summer of arcade games
Maybe ryse (if not pushed back to next gen)
South Park the game by THQ
Splinter Cell Blacklist by ubisoft
Something by square enix
A new music game by Harmonix
probably black ops II
windows 8 and Windows Phone 8 games and Inyeraction
Woodstock musk service revealed
Maybe the xbox kinect fitness stuff
probably skype along with other apps
Internet Explorer on xbox
hopefully a tease of next gen