Microsoft released Clinic 10052: Introduction to Enhancements in Microsoft Office Communications Server 2007 R2

"This 1-hour clinic describes the various enhancements in Office Communications Server 2007 R2 clients and devices, conferencing, mobility, Office Communicator Web Access 2007 R2, and voice.

This clinic covers the following topics:
- Office Communications Server 2007 R2 clients and devices
- Audio, video, and Web conferencing
- 2007 R2 version of Office Communicator Mobile
- Office Communicator Web Access 2007 R2
- Call delegation
- Response Group Service
- Team-call group"

https://www.microsoftelearning.com/eLearning/courseDetail.aspx?courseId=112782&tab=overview