For my Front End (a.k.a. Home) server I used the option to export all my users (actually only their settings/contacts etc.), deactivate/uninstall and then install RTM of OCS 2007. For the other servers I also deactivated and uninstalled RC versions and reinstalled the RTM versions. There were a few gotchas but luckily nothing major.
I ran into a documentation error in the dbexpimp.exe suppport tool/help file included with OCS 2007. It states that the syntax for import is dbimpexp.exe /hrxmlfile:"c:\SavedUserData.xml". It's obviously "dmpimpexp.exe /import /hrxml...."The other issue was a bit more quirky. After reinstalling the OCS 2007 Front End I reassigned all users from ADUC to the new RTM server (With the same name as the old). After that I imported the user data using dbimpexp.exe and everything worked fine (Presence, IM, voice and conferencing). While upgrading the Mediation Server I noticed that all users where disabled, but since all users worked and I was running a RC version of the MMC from the Mediation Server I concluded it was a co-existence issue.
Later I was testing PIC connectivity. I created a new Live account and from Live Messenger added sip:email@example.com. Nothing happened on the OC side. I then added my messenger test account from OC and presence and IM was now working, while this was good it still wasn't OK - I should receive a pop-up in OC. Then I took a look at my user from the OCS MMC and immediately noticed that all users still were marked as "disabled" (Even though they were fully functional). I then ran through all users and enabled them one-by-one. After a Sign Out and Sign In in OC I finally recieved my pop-up (Although I'm not quite sure why and if this has anything to do with PIC not popping up requests, it's still a fact that the users were both disabled from the MMC GUI and functional at the same time). This problem is most likely due to a fault on my side or only related to migrations to RTM.
The last issue was federation with Microsoft (other partners worked fine) after troubleshooting and debugging a bit I suddenly remembered that I had seen a mail a few days ago
All OCS services will be down for the RTM upgrade.
Scheduled Downtime: Friday 8:00am – Saturday 9:00pm services will be down intermittently during the OCS upgrade.
So I guess Inceptio reached RTM before Microsoft ;-)