L4D update released

From Steam News:

Game and client changes

■ Introduced fatigue to the melee attack in versus mode. You will see a HUD display when your melee swing is cooling down
■ Boomer vomit will now pass through common infected
■ Addressed some surround sound detection issues
■ Fixed a rare crash when exiting Left4Dead on Windows Vista
■ Fixed a case where the complete all expert campaigns achievement was not being rewarded

Dedicated server changes

■ Corrected an issue where Windows based dedicated were sending spurious shutdown notifications to the master causing them to delist temporarily
■ Fixed dedicated servers not resetting the versus team swap correctly--you could join a dedicated server that had a previous game that was swapped and arrive on the other team than what was selected in the lobby
■ Renamed the tags for sv_search_key to use "key:" in the server tags instead of "sv_search_key." This should help with issues of the 63 character limit of server tags
■ Fixed an occasional server crash related to voting

There's also a blog update: Building a Better Apocalypse.