Exchange 2007 Service Pack 2 Released

Read the EHLO accountment:
http://msexchangeteam.com/archive/2009/08/25/452095.aspx

Download SP2:
http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=4c4bd2a3-5e50-42b0-8bbb-2cc9afe3216a

SP2 requires Windows Installer 4.5:
http://msdn.microsoft.com/en-us/library/cc185688(VS.85).aspx

See what Active Directory changes are being made:
http://go.microsoft.com/fwlink/?LinkId=161017