According to Valve's blog, Left 4 Dead 2 DLC "The Passing" will be available for download later this week. This episode of the shooter features the historic meeting between the zombie-hunters in Left 4 Dead and the zombie hunters in Left 4 Dead 2, as well as an appearance by everyone's favorite butt-rock metal band The Midnight Riders. It will run you 560 Microsoft Points ($7) on Xbox Live. The PC price (if any) has yet to be announced.
Speaking of video game band The Midnight Riders, you can download a couple of their tracks for Rock Band right here, and a brand new power ballad, "Save Me Some Sugar," will be featured in "The Passing."