The lack of SDK clearly has not discouraged community mappers, however, as there are a number of promising projects in the works. Some interesting WIP maps that have popped up include Warehouse 23, Parking Finale, the Fatal Attraction campaign, and a new media release for a map in the Urban Decay campaign.

Also, Episode 6 of the Survivors Diary podcast was recently released. Among many other things, they discussed their playthrough of City Minami campaign's alpha release.

Though this is not exactly L4D news, it is great news for fans of co-op gaming: Sven Co-op 4.0 Beta has been released. Sven Co-op is a co-operative mod for Half-Life 1 in which players work together against AI enemies and solve puzzles as a team. v4.0 is the best SC release yet, with many new features and improvements. You can co-operatively play the original HL story, They Hunger Co-op Ep1, or choose from hundreds of original user-created maps. Head over to SvenCoop.com to download the mod (you'll need HL1 installed).