Windows Server 2012 RTMbecame available a few days ago. Many of you have been busy downloading and testing this latest and greatest version of Windows Server and now you're waiting to find out when you can install Exchange on it.
If you’re testing or planning to test Exchange Server 2013 Preview, it is compatible with Windows Server 2012. For details, see Exchange 2013 System Requirements.
Exchange 2010 SP2 is not supported on Windows Server 2012 (see list of supported operating systems in Exchange 2010 System Requirements). We’re working on updates to add Windows Server 2012 support to Exchange 2010 and will announce on this blog when we have more to share.
--> Please see the rest on the blog : http://blogs.technet.com/b/exchange/archive/2012/09/14/windows-server-2012-and-exchange.aspx