After over a year of public testing, Valve will officially launch Left 4 Dead 2's 'Cold Stream' DLC later this month. It packs versions of original Left 4 Dead campaigns Blood Harvest, Crash Course, Dead Air and Death Toll, as well as the community-made Cold Stream. On top of that, a patch launching alongside will make all of the game-altering mutations available at all times.
The DLC and accompanying patch will launch on July 24, Valve revealed in a blog post. Valve put Cold Stream up for public testing last March, followed by the remaining L4D campaigns (No Mercy had launched before). Now, thanks to the wonders of Valve time, it's finally ready to roll out.
Valve has been rotating mutations weekly since February 2010, with only one available at any time. Their weird and wonderful effects have included turning all enemy infected in Versus into tanks with 'Taaannnkk!,' the infinite ammo M60 madness of 'Gib Fest,' and mode-mashup 'Versus Survival.' When the new patch launches in the 24th, you'll be able to play any of them whenever you want.
While the Cold Stream DLC will be free on PC, Valve will most likely charge on 360.
