After about a year in beta (classic Valve), the Left 4 Dead 2 DLC known as Cold Stream is finally about ready to launch. You can expect the content July 24 on PC, Mac, and 360.
Cold Stream, if you're unaware, contains six new maps: Cold Stream, Blood Harvest, Crash Course, Dead Air, and Death Toll. There are also some "surprises and details" to come from Valve at a later date. For now, it can be said all mutations will be available at all times, including user-made ones.
As ever, we expect this to be free on PC and a relatively small amount on 360. Confirmation and more info as it comes in.