Steam News has word on the release of the promised patch to update Aliens vs Predator, which is now available along with an open beta of the promised dedicated server for multiplayer play. This forum post has instructions on how to access and run the beta dedicated server, and this forum thread has the complete patch notes, which follow.

Multiplayer
- Added client-side support for dedicated servers
- Ranked match lobbies will no longer end after every match

Due to the demand from the community and better than anticipated progress on the server software, we have decided to release the dedicated server as an Open Beta rather than a Closed Beta, and make it available to all. To access the Dedicated Servers from the PC client, go to Player Match > Browse > change the “server type” filter to “Dedicated (Internet)” and then click browse. Please note that the initial availability of servers may be limited.

The full and final patch notes are below;

General
- Stability improvements to address rare and infrequent hangs
- Implemented a workaround for missing audio issues with certain hardware (SoundBlaster X-Fi, Realtek onboard, etc.)
- Fixed save games being lost or corrupted if connection to Steam is lost or if user switches to offline play

Multiplayer
- Added client-side support for dedicated servers
- Ranked match lobbies will no longer end after every match
- Fixed XP being incorrectly affected by offline play (though only in the local stats; this will be corrected next time you connect to multiplayer)
- Fixed other players sometimes appearing to have the wrong weapon or continuing to fire indefinitely after dying
- Fixed rare issue where players would be temporarily invisible
- Fixed some selection of servers and players in menus sometimes being incorrect