Microsoft maintains and provides Excel docs for the various versions of server and workstation operating systems. They have just updated their list to include Windows Server 2012 and Windows 8.
It’s always interesting to see “what’s new” in GPO for the latest OS, and it’s a great reference to have.
Want the Excel docs for earlier OS’s? You can still download the Excel reference docs for Windows Server 2003, Windows Server 2008, Windows Server 2008 with R2, Windows Vista, Windows Vista with SP1, and Windows 7 here: Group Policy Settings Reference for Windows and Windows Server