I received the following information and links from our Microsoft TAM.  Enjoy… 
“2007 Daylight Saving Time Transition Q&A” at http://www.microsoft.com/communities/chats/default.mspx
The most common questions and answers have been captured at: http://blogs.technet.com/dst2007/
Also, you want to be sure to view the Video Demos at:  http://msexchangeteam.com/archive/2007/02/21/435543.aspx#435553 (Excellent resource!)
Use the Planning wizard – http://www.microsoft.com/dst2007 [IT Professional]
Here is the article on patching order (including changes for OWA):
Lifecycle Information
Lifecycle (alpha search) – http://www.microsoft.com/lifecycle (scroll to bottom)
Lifecycle Support Service Packs – http://support.microsoft.com/gp/LifeSupSps
Patches & Tools
CDO – Exchange 2003 SP1 – http://support.microsoft.com/kb/931978/
CDO – Exchange 2003 SP2 – http://support.microsoft.com/kb/926666/
DST2007 impact on Dev Tools and applications:
Also, an internal Wiki (http://mswikis/dst2007/Wiki%20Pages/DeveloperGuidance.aspx) should be of good assistance for us to understand some of the issues associated with the DST change.
What is performance of the rebasing tool?
If you go to http://support.microsoft.com/kb/930879/  and search for run time, you will see following
Run time may be long.  Msextmz.exe is single-threaded, therefore, it could take many hours to run the tool against many mailboxes.
For reference, Microsoft IT was able to update approximately 53,000 mailboxes in 16 hours by using nine clients. This equates to an update rate of 6.13 mailboxes per minute per client. The number of invitees in a meeting request should not affect the run time of the Update mode. This is because from the client perspective, sending a meeting update to one recipient takes the same time as sending a meeting update to 100 recipients. The number of invitees does affect the number of copies of the meeting update. However, that is an issue of mail flow, not of run time.
The number of invitees in a meeting request should not affect the run time of the Update mode. This is because from the client perspective, sending a meeting update to one recipient takes the same time as sending a meeting update to one hundred recipients.
The number of invitees does affect the number of copies of the meeting update. However, that is an issue of mail flow, not of run time.