I found a posting released today about a new Hotfix from Microsoft for Outlook 2007 which is promising to update performance and responsiveness.
http://support.microsoft.com/hotfix/KBHotfix.aspx?kbnum=961752&kbln=en-us
I’ve downloaded and installed and it seems faster to me, but I have a pretty small mailbox.. Others on this Lifehacker post are saying it works tons better:
http://lifehacker.com/5185259/outlook-2007-update-boosts-performance-and-responsiveness
Thought I’d share if it’s useful to you..