New update rollups are available for Exchange Server versions 2007 and 2010:
Exchange 2010 SP2 RollUp 4: http://www.microsoft.com/en-us/download/details.aspx?id=30478
Exchange 2007 SP3 Rollup 8: http://www.microsoft.com/en-us/download/details.aspx?id=30479
A list of changes can be found here:
http://support.microsoft.com/kb/2706690
and here
http://support.microsoft.com/kb/2734323
