Today Microsoft announced the availability of Windows 8 Release Preview as well as Windows Server 2012 Release Candidate. But what I really would like to point it out is the new Documentation around Security Features that we are releasing for this milestone. Check it out this list:
Access it from here: http://technet.microsoft.com/en-us/library/hh832031 and also make sure to check it out the Windows Server 2012 Release Candidate documentation for Server Roles and Technologies at Microsoft TechNet Library.
Explore, test it and make sure to leave your feedback!