What is it?
With Microsoft Office Communications Server 2007 Speech Server, you can develop and deploy interactive voice response (IVR) applications. Speech Server combines speech technologies, Voice over IP (VoIP), and telephony capabilities into a single system and a single code base.
The MS official site says:
Powerful speech-based interfaces, available in your language, will enhance the user experience and let people access information more naturally and effectively wherever they are. Microsoft’s speech technology already powers great ready-to-use applications like Outlook Voice Access in Microsoft Exchange 2007 Unified Messaging, Windows Speech Recognition on Windows Vista, Speech Server on Office Communications Server 2007, and Voice Command on Windows Mobile. In addition, developers can leverage powerful APIs and tools to build their own speech-enabled applications using the Speech Server Developer tools for Visual Studio 2005 and the System.Speech API in .NET 3.0.
It look like its some sort of API solution, that does provide ISV’s with an interface to the OCS 2007 telephony system.
I will update when i get more info