Valve has announced that the Cold Stream DLC will be released on July 24 on the PC, Xbox 360 and Mac. The DLC contains: Cold Stream, Blood Harvest, Crash Course, Dead Air, Death Toll and No Mercy maps.
“After months *cough*year*cough* of play testing not just the Cold Stream campaign on the PC but the entire DLC consisting of Blood Harvest, Crash Course, Cold Stream, Dead Air, and Death Toll, we are ready to release on the Xbox 360,” read the Left 4 Dead blog.
“The date will be July 24th. There are some other surprises and details we will give you later but for now we just want to confirm an often requested feature. With the update going out at the same time (also for the PC), all of the mutations will be available at all times. This will allow players to choose to match into games playing Taannkk!, Gib Fest, or even a user created mutation like Confogl.”