A Steam client update is now available. To apply the update, click the File menu inside of Steam and then select "Check for Steam Client Updates...". The specific changes include:
Steam
Prevent Windows 7 audio ducking in games when Steam voice chat is used
Fix a common crash caused by certain Flash using websites in the in-game overlay browser
Increased default in-game overlay browser window size when running in a large screen resolution
Fix a bug with Steamworks networking connections not resuming immediately when more than 4 are created at once