As noted in last night's anticipatory announcement on Steam, today is the release date for Left 4 Dead, and according to the gold announcement from a few days ago, the game should unlock on Steam in a matter of 60 seconds: "Those who pre-order the game via Steam save 10% off the regular price and may pre-load the game so they are able to play at 12:01 am EST on November 18, 2008 when the game is made available."