According to IGN and Joystiq:
"11:11: A video is showing of Gears of War with hundreds of enemies running down the road to show off new tech. Water and splash effects are shown, again using Gears of War on updated engine.
11:10: "Imagine what Gears of War would look like if we launched it today." CEO comes out to talk about updates on Unreal Engine. Ambient Occlusion technology is one thing they've added. This is good for more realistic shadows."
Update
Sorry about that, Here is the link to the images:
http://www.joystiq.com/2008/02/20/joystiq-live-from-the-microsoft-gdc-keynote/
180°
160°
30°
100°
Ad 
20°
10°
10°
10°
10°
