Exchange 2013 has been announced
http://www.microsoft.com/exchange/en-us/exchange-preview.aspx
Exchange 2013 Preview Can be Downloaded From here
http://technet.microsoft.com/en-US/evalcenter/hh973395.aspx?wt.mc_id=TEC_116_1_33
Stay Tuned, I am in the preparation of Posting More on Exchange 2013.
Messaging & Collabration Blog 