KC just pointed out to me that Office 2007 Beta 2 is now available for everyone to download and test. In order to get it, you should go to this page:
http://www.microsoft.com/office/preview/beta/getthebeta.mspx
If you are on Exchange 2007 BETA or have installed the Exchange 2007 CTP, this is something you might want to look into and test as Outlook 2007 has several features that work only against Exchange 2007 Server.
Happy testing,
Updated Jul 01, 2019
Version 2.0The_Exchange_Team
Microsoft
Joined April 19, 2019
Exchange Team Blog