Gabe Newell has revealed that Valve’s latest Source powered shooter, Left 4 Dead, should be getting a demo for the Xbox 360 and PC versions of the game. An exact release date for the demo was not revealed, but it is known that the demo will feature the first part of one of the four campaigns. The most exciting bit of news coming from the announcement is that Gabe revealed that the demo will feature both single-player and co-op gameplay. Look forward to slaughtering zombies with your friends November 21.