Hoping to axe a few zombies in the face at the Penny Arcade Expo next weekend? Valve sent out a confirmation today that, indeed, Left 4 Dead 2 will be playable at the Seattle-based convention. In fact, they"ll be taking the opportunity to debut "Dark Carnival" -- the third of five new campaigns to be revealed for the co-operative shooter.

Both the Xbox 360 and PC versions of Left 4 Dead 2 will be at PAX next week, with different sections of the game available for play at Microsoft and Valve"s booths. Valve also plans on showing off a handful of the 20-some new weapons and items they"ve added to the zombie survival game.

That all sounds fine and dandy, but don"t overlook what"s probably the most important revelation about Left 4 Dead 2 and its "Dark Carnival" campaign: Zombie clowns. Depending on your stance on live clowns, the addition of flesh-eating corpse clowns might actually steer some people away from (or toward) Left 4 Dead 2.