Updates to Left 4 Dead have been released. The updates will be applied automatically when your Steam client is restarted. The specific changes include:

Left 4 Dead
Fixed problem with add-on installer failing to install add-ons properly on some versions of Windows
Transition screen now shows campaign and map names for add-on campaigns
Bug fixes and enhancements for Novint Falcon controller
Get the full article at store.steampowered.com