A great resource I am using for years already to proactively read through the Microsoft KB’s is kbupdate.info a monitoring system that scans the entire Microsoft Knowledge Base every night. Now that Windows 8 and Server 2012 are out and Microsoft starts publishing KBs for it, you can track them easily via kbupdate.info
Below just some random KB’s I found interesting to know about.
Remote Group Policy updates are visible to users
ADM files are not present in SYSVOL in the GPMC Infrastructure Status option
Unpredictable behavior if you migrate a roaming user profile from Windows 8 to Windows 7
You can only log on as "Other user" when the "Do not display last user name" Group Policy setting is enabled in Windows 8 or Windows Server 2012
Group Policy preparation is not performed when you automatically prepare an existing domain for Windows Server 2012