Some of the major improvements and critical bug fixes in this rollup include three new registry entries to help speed up troubleshooting of abnormal database size/log file growth.
Microsoft also made a change to the UM Auto Attendants configuration in the Exchange Management Console so that it is aware if your time zone follows daylight saving time.
Microsoft also fixed another bug to allow access to the OWA Virtual Directory via the Exchange Management Console in an environment coexisting with Exchange 2010. This is now possible if the Exchange 2007 server was upgraded from Exchange 2007 SP1 to SP2.
In addition, users that want to add BPA health rules to a server with no Internet connection can do so by downloading and installing the update rollup on the server. Before this update, BPA rules were only available on the Web. In Exchange 2007 SP2, Microsoft also added a work item that lets the company ship updates to the BPA health check rules through the rollup and the Web.
For more information, KBA 972076 lists all of the fixes included in this rollup as well as information on system requirements and rollup installations.