Update Rollup 6 for Exchange Server 2007 Service Pack 1 has been released. Here are the fixes included in this rollup:
1) Fix for a security issue which has been assigned a severity rating of critical. More information about the issue can be found in the Microsoft Security Bulletin MS09-003. 2) Fix to allow Internet Explorer 8 to be used for Outlook Web Access (OWA) 2007. This does not include the OWA 2007 S/MIME control. We are still working on some changes in the control to make it work better with Internet Explorer 8. We will be releasing an updated version of the S/MIME control in a future rollup. Users using the S/MIME control should continue to use Internet Explorer 7.
KB 959241 has more details about this release and a complete list of all fixes included in this rollup.