At Microsoft's E3 press conference moments ago, legendary game designer Cliff Bleszinski showed off some very impressive gameplay for Gears of War 3, including four-player co-op. Cliff also mentioned a new mode for the game: "Beast Mode." No info yet on what that actually is, but we can't wait to find out.
Also of note in the trailer: The first look at Gears 3's female soldiers, complete with prominent breast-armor. We also got a look at weapon-swapping between players. Very, very nice.