Left 4 Dead Survival pack releases April 21

Destructoid reports that Valve have confirmed the release date, April 21, for the free Left 4 Dead ‘Survival pack’ we reported on last month. The pack will contain the other two maps, Dead Air and Death Toll, for versus mode, as well as the new “Survival” mode in which you aim to survive the hordes for as long as possible. It’s coming for both 360 and PC, free on both, so nobody has an excuse to not get it- there will even be a special version of the game released at retail with the extra content for those of you who don’t already have the game.