You can watch it here: http://www.ign.com/events/e3/2012/live-video
or on Spike TV.
Game List:
Halo 4
Splinter Cell Blacklist
Gears of War Judgement
Madden/Fifa 13
Ascend: New Gods
South Park: The Stick of Truth
Dance Central 3
Call of Duty: Black Ops 2
Dead Space 3
Medal of Honor: Warfighter
Starwars: 1313