Features Supported by the Editions of SQL Server
2012
http://msdn.microsoft.com/en-us/library/cc645993(v=SQL.110).aspx
2008R2
http://msdn.microsoft.com/en-us/library/cc645993(v=sql.105).aspx
2008
http://msdn.microsoft.com/en-us/library/cc645993(v=sql.100).aspx