I just re-checked the SP1 KB article mentioned earlier in the posting Exchange 2007 SP1 Beta 2 information.
And noticed this in the last part of the KB article -
... Traditionally, beta support has been limited to public forums. Beta products have never been supported in a production environment. However, for this beta version, limited support is available through Microsoft Customer Service and Support for customers who want to integrate Communications Server 2007 and Exchange UM features until the release of Exchange 2007 SP1. To receive support through the Microsoft Customer Service and Support organization, you must strictly meet the following criteria:
- Exchange 2007 UM SP1 Beta 2 role deployed to a dedicated server.
- No additional roles deployed with SP1 Beta 2 within the environment.Warning Additional Exchange roles will start an Active Directory Schema update to the production environment when SP1 Beta 2 is installed.
- Only 64-bit code will be supported.
- You must be trying to integrate with Communications Server 2007.
These are similar to the requirements that are imposed on OCS TAP customers - but new is of course actual public support for SP1 Beta 2 on the UM role.
Btw. if you want more info on Exchange 2007 UM and OCS integration then take a look at Introducing Unified Messaging in Office Communications Server 2007 environment.