A new patch was released recently that helps performance on Outlook 2007 noticeably.
Important Information for BCM users:
PLEASE READ THIS ARTICLE BEFORE INSTALLING THE UPDATE: http://support.microsoft.com/kb/935569
Where do I get it:
The Outlook update can be found here: http://www.microsoft.com/downloads/Browse.aspx?DisplayLang=en&nr=20&productId=50663FD1-DBAD-4705-B915-E4CF683E70FE&sortCriteria=date
The BCM patch can be found here: http://www.microsoft.com/downloads/details.aspx?FamilyID=b1fadb55-e4e1-4f67-a69a-3e6bf9b130f0&displaylang=en
KB Article information:
http://support.microsoft.com/kb/933493
http://support.microsoft.com/kb/932086