If Left 4 Dead has been collecting a little virtual dust in your Steam account it might be time to brush it off and fire it up.  Ars Technica has some information for you not only about the new downloadable mission with new weapons and a beastie but also information on what Valve is calling Weekly Mutations.  This sounds similar to the mutations in Unreal Tournament and every week there will be something a little different about the game.

“Are you ready to jump back into Left 4 Dead 2? This Thursday the next set of downloadable content will be released. Called “The Passing,” the content provides a new mission where the survivors from the first game meet the new set of characters from Left 4 Dead 2. Of course, that’s not all.”

Here is some more Tech News from around the web: