Just for the record but very important for installing Office Communications Server 2007 in your production environment.
At this moment there are 2 OCS2007 bits available:
(1) bits located at MSDN (MSDN product key)
(2) bits located at the Microsoft download site (180 days time bombed)
When installing the MSDN-bits in your production environment there is NO supported upgrade scenario available. This means uninstall your complete environment and reinstall with the correct RTM bits (licensed version)
When installing the RTM-bits evaluation (180 days time bombed) in your production environment there is an legal upgrade path to RTM Full licensed. After 180 days you will upgrade the RTM eval bits with the RTM full licensed bits in an in place upgrade (your configuration settings will be saved)
Additional information on RTM availability:
RTM full licensed bits are only available for TAP participants and customers with an enterprise agreement. Should your organization not have a current enterprise agreement in place with Microsoft, General Availability of the OCS 2007 and MOC 2007 RTM software is scheduled for September 2007.