Set for release on November 17, the title adds melee combat to enable deeper co-operative gameplay, with items such as a chainsaw, frying pan, axe, baseball bat, and more.

Introducing the AI Director 2.0, L4D's dynamic gameplay is taken to the next level by giving the Director the ability to procedurally change weather effects, world objects, and pathways in addition to tailoring the enemy population, effects, and sounds to match the players' performance. The result is a unique game session custom fitted to provide a satisfying and uniquely challenging experience each time the game is played.

After debuting "The Parish" campaign (set in the New Orleans' French Quarter) at E3, the Comic Con showing will unveil "Swamp Fever", the second of the five campaigns shipping with L4D2 this fall. The game will be playable in the EA Gaming Lounge Presented by Xbox 360 from 2-9 pm Thursday-Saturday, and 12-5 pm on Sunday. The EA Gaming Lounge will be located in the Hilton San Diego Gaslamp Quarter Hotel, 401 K. Street.

In addition to the new campaign, Valve is also planning to unveil a few more of the 20-plus new items

Featuring new Survivors, boss zombies, weapons, and items, Left 4 Dead 2 offers a much larger game than the original with more co-operative campaigns, more Versus campaigns, and maps for Survival mode available at launch.