Q: Is Office Communicator 2007 a licensed product?
A: Yes, unlike Exchange CAL that gives you access to Outlook, Office Communicator i a separate product, not covered by the Office Communications Server 2007 CAL license.
This means that you have to purchase these license separate. If you already have one of these Office Suites, the software license is included in the suite:
Microsoft Office Pro Plus 2007
Office Enterprise 2007