The L4D Creation Tools will be released sometime by the end of the week, with lots of enhancements: for example, the custom missions will be more prominent within the userbase, while the matchmaking system will be updated to reflect this. Add to that the fact that installing the Left 4 Dead custom campaigns and maps will be a breeze, and you’ll have some reasons to forgive Valve for announcing Left 4 Dead 2 so soon.
The devs say: “When creating or searching for a lobby, a new option named “Add-on campaign” will let you select from among the add-on campaigns that you have installed. You can then find games or lobbies as well as create a lobby for that campaign. You can invite your friends, too. If they do not have the campaign installed, they will automatically be offered and an option to download it.”
Also, once this update is live, the source files of all the original campaign maps will be released to the public, making it easier for everybody to customize and create new content. Of course, this could mean that a release of a sequel would be even more pointless, but we’re not here to discuss that right now!