I sat in on an Office Communications Server 2007 design discussion and here are a few points that we covered that I felt noteworthy.

The client must have Microsoft Office Communicator installed. I guess this must be different from Microsoft MSN client and Microsoft Windows Live client.

As part of the unified communications concept, you have “One number” which means that a user can be contacted on different devices/numbers at the one number. Sort of like smart routing.

3rd party Internet awareness with AOL/Yahoo must be subscribed to a service from Microsoft

Exchange 2007 server Unified Messaging role – can route phone calls, read your email to you over the phone, read your voicemail to you over the phone, etc. I believe alot of PBX and other hardware dependencies must be in place for this to be a reality.

OCS 2007 archiving role…can act as instant messaging journaling. Archiving can be journaled by Symantec Enterprise Vault. The benefit of this is that e-discovery for legal can take place in one technology for a particular query instead of having to use Facetime archiving search tool for e-discovery of IM history.