Microsoft recently posted information that reveals planned changes to the support matrix. These changes won’t go into effect for the upcoming spring “Leo” release but would likely go into effect during the fall “Vega” release.
A few items on the list that are important to note that are losing support on the platform side:
Windows Server 2008 & Windows Server 2008 R2
SQL Server 2008 & SQL Server 2008 R2
Internet Explorer 8 & 9
Also mentioned was removal of the CRM 2011 “Information” forms on the updated entities that have the new CRM 2013 forms available.