Just minutes ago Epic head Cliff Blezinski pulled out a live demo of chest-high wall shooter Gears of War 3, and showed off some of its four-player, story-based co-op. Playing with several other producers, Marcus and the other gears (including the new female soldiers Anya and Sam) fought hard against the "Lambent," the game's new, rather hideous foe.
The Lambent mutated on the fly, with one beast turning into a tall tentacle thing that could shoot over Cliff's cover, denying him the wall he hugged for his very life. Also shown were the return of the Hammer of Dawn beam weapon, and some quick shots of the new pilotable mech suits. As if the gears' armor wasn't bulky enough!
Cliff hinted at a new mode called "Beast", to be detailed later on! Keep checking back as more info comes in!