I have a few comments. This was a very informative article, it helped immensely in preparing my company for this. However I ran into 2 issues, I am sure everyone else has experienced:
1) Appointment notification storms get bounced to all my users when I perform the rebase.
2) My users have no idea what was changed and what should stay appropriate etc....
A couple suggestions for those that may run this.....
1) Expect a lot of appointment notifications being bounced to your users, make them aware of this before you run it! This may also cause space issues for those with extremely tight quotas and large mailboxes.
2) I may look into writing a script that sends my users a copy of the transactions logs that are spit out for each one of them. This will help users to identify the changes made to their calendars. This could probably be accomplished easily through a vbscript. anyone tried yet?
-Nick