Valve have officially confirmed that the first major update for Left 4 Dead 2 - titled, as in the way of this new-fangled DLC, "The Passing" - will be landing on on Thursday, April 22, US time, so Aussies should see it Friday. The release also contains word of the new features, hinted at yesterday:

The Passing also introduces a series of weekly game mode events dubbed "Mutations." These week-long runs of new gameplay modes range from "Realism Versus" mode to "Chainsaw Massacre," which gives all players chainsaws with an unlimited supply of gasoline. There are over 20 Mutations planned, each playable on all L4D2 Campaigns. Mutations are exclusively available to owners of "The Passing" DLC.

In addition, "The Passing" offers a new co-operative challenge mode of play, support for infected bot play in Versus, a new "uncommon common" zombie class (the fallen survivor), melee weapon (golf club), and firearm (M-60).

This'll cost you 560 Microsoft points if you're picking it up on Xbox 360 or AUD$0.00 if you're getting it on PC. Don't forget to check out our buy page for our pricing list if you still haven't got it!@#