FYI all...our testing so far with the Outlook 2007 patch this month (MS09-060) shows that it is introducing some of the improvements made in Office 2007 SP2 and several previously-released Outlook 2007 hotfixes (specifically KB969907). Basically after installing and restarting Outlook or the machine, the first launch of Outlook will run a process which reindexes or otherwise optimizes your PSTs. The message box is shown in the KB link to 969907. Depending on the size/fragmentation of the PST, it can take a substantial amount of time (30+ minutes) for this to complete, and your users may wonder what is going on.
This patch has also broken an Outlook add-in we use (Cisco MeetingPlace), which we still don't have a working solution for.
Remember...test, test, test!