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 s 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.