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

Steam Client

• Added Guest Passes functionality - allows owners of certain Steam games to let their friends play games for free, for a limited time trial
  
• Changed Steam client auto-update mechanism to first acquire updates in the background and then ask user whether to restart & apply
  
• Added Favorites area and collapsable status categories to 'My Games' list
  
• Added 5 new colored skins (Default, Ice, Sand, Obsidian, and Grey), selectable in "Settings"
  
• Added 'next' button to Steam news window, allowing multiple messages to be viewed in a single session
  
• Fixed client attempting to update some games which user does not own; was occuring when user had played game during a Free Weekend
  
• Fixed games purchased via PayPal not working in offline mode