Microsoft has released Service Pack 1 for Office 2007.
And, best of all, the list of fixes says they have addresses the poor performance in Outlook 2007 when you have a large PST file (i.e. lots of stored email messages). The Excel sheet listing what’s fixed in the SP references Microsoft KB935517 “You experience performance issues in Outlook 2007 when you work with large .pst files or with large .ost files.”
The bane of my Outlook existence may soon be gone!
Gonna install tonight and keep my fingers crossed.