Go read the announcement at http://blogs.technet.com/b/server-cloud/archive/2011/11/10/system-center-operations-manager-2012-release-candidate-from-the-datacenter-to-the-cloud.aspx
This is the first public release since I am part of the team (I started in this role the day after the team had shipped Beta) and this is the first release that contains some direct output of my work. It feels so good!
Documentation has also been refreshed – it starts here http://technet.microsoft.com/en-us/library/hh205987.aspx
The part specifically about the APM feature is here http://technet.microsoft.com/en-us/library/hh457578.aspx