We already knew the first piece of downloadable content for Valve's zombie shooter, Left 4 Dead, was due to arrive soon but now Microsoft has confirmed a specific launch date for the Xbox 360 this April 21. No specific date has been mentioned for PC users as of yet, though a simultaneous release is widely expected, along with the Left 4 Dead: Critics Choice Edition that contains the original game plus the Survival Pack.

As previously reported, the pack includes the new survival mode, where up to four players must hold out against a never ending wave of infected for as long as possible, as well as the addition of the Dead Air and Death Toll campaigns in Versus mode. This DLC will be available at no cost for both Xbox 360 and PC users.