SP2 for Office 2007 has been released and there are some major improvments with regards to Outlook performance, especially in cached mode. These were back ported to the Feb. cummulative update but are also included in SP2 along with other stuff.

http://www.microsoft.com/downloads/details.aspx?FamilyId=B444BF18-79EA-46C6-8A81-9DB49B4AB6E5&displaylang=en

Wow..... the high availabilty changes in Exchange 2010 are a game changer. If it all
works as well as described every Exchange shop in the world will be redundant after
adding a second server. I remember asking about mailbox replication at the MVP
summit a few years ago but they weren't there yet. I'm glad to see they kept on that
direction and hope this turns out to be a solid feature. Paul has a good rundown of the
details involved:

http://www.robichaux.net/blog/2009/04/exchange-2010-availability.php

The first large scale review of Exchange 2010 is up (one of many) and it sounds like the

next version of Exchange might make up for all the sins 2007 did against the admins.  Only

time will tell...

http://www.infoworld.com/d/applications/first-look-exchange-2010-beta-shines-485