According to Advance Notification for Microsoft Patch Tuesday February 2011, 12 security bulletins will be released. Out of 12 Three are rated as “Critical” & rest of the bulletins are awarded “Important” rating. 11 bulletins fixes vulnerabilities found in various windows Operating systems and the last bulletins fixes exploits in Microsoft Office Suite.
Nine bulletins requires to restart your system after applying the patch and rest three may require restarting which may depend upon individual system configuration. Recently found vulnerability in MHTML Protocol is not addressed in this update which means you have to wait for some more time till the patch is made available Microsoft.