New Co-operative Game Announced for Team Fortress 2 and Trailer

You must stop a lethal horde of robots from deploying a bomb in one of Mann Co.'s many strongholds
A new co-operative game for free-to-play online action title Team Fortress 2 (TF2) will be available tomorrow, August 15th, 2012, Valve announced. Mann vs. Machine (MvM) lets you and five friends fight a lethal horde of robots on all-new maps, with the opportunity to upgrade abilities and weapons along the way. You will band together to survive all of the robot waves in a variety of missions to earn incredible loot and unlock new achievements.
A trailer is now locally mirrored.