An update to the Steam client and HLDS update tool has just been released. Steam will update itself automatically when you restart. Here is a list of the changes:

STEAM CLIENT CHANGES / ADDITIONS:
Improved error messages when Steam system is busy
Improved error messages when login fails
Improved ability to monitor system performance
Improved startup times
Improved cache loading behavior for single-player games
Added features for CyberCafes
Improved use of large cache files
Keep local account information more up-to-date
Improved response to ContentServer connection loss
Improved server communication
Improved command-line handling
Added opt-out options for marketing messages via the Settings dialog
Changed monitor to show games instead of caches
Smoothed out monitor bandwidth usage display
Added "browse games" button -- opens storefront

HLDS UPDATE TOOL:

Improved handling of encrypted files
Added "-command list" option to list the valid "-game" flags you can specify