Valve announces The Passing, the first DLC for Left 4 Dead 2, which will bring the survivors from the original Left 4 Dead into the zombie shooter sequel for new single-player, multiplayer, and co-operative gameplay, saying the add-on will "include new arenas for Survival, Versus and Scavenge mode and introduce a new co-operative challenge mode of play." Here's a bit on the add-on, which is currently expected in Spring 2010. "The Passing will become the most important campaign in the Left 4 Dead story, as all the Survivors are being called together in one campaign," says Doug Lombardi, VP of marketing at Valve. "It will also be a huge offering of new gameplay content, with something new for every game mode plus a new uncommon common and weaponry." Word is:

Targeted for release in early spring, "The Passing" takes place just after the Dead Center campaign of L4D2. Set in a small town in rural Georgia, players assume the role of the L4D2 Survivors as they meet with the L4D1 characters.

In addition to the new co-operative campaign and associated narrative, "The Passing" will include new arenas for Survival, Versus and Scavenge mode and introduce a new co-operative challenge mode of play. The Passing will also include a new "uncommon common" zombie class, melee weapon, and firearm.