To apply the update, click the File menu inside of Steam and then select "Check for Steam Client Updates...". The changes include:

Steam Client

• Added Czech and Hungarian language option
  
• Optimized where clients get the list of available subscriptions
  
• Under-the-hood Steamworks API improvements for future titles
  
• Changed desktop .ico files and games list .tga files to be downloaded on demand, instead of being a blocking download during startup
  
• Fixed serverbrowser not refreshing the internet list the first time it was displayed if it was right on startup
  
• Fixed hardware survey not always saving that you said you did not want to participate
  
• Fixed IMs from popping up while in-game
  
• Fixed the bug that removed one character per line of copied text when pasting into a chat text entry
  
• Fixed a crash on shutdown in some Source engine games
  
• Fixed some bad text in Polish in the Friends list