Source: snapvoip.blogspot.com

Just like with Netscape, where M$ got lucky, the software giant is again into the catch up or me too game. This time with VOIP. But this time it seems to have a plan.
Leveraging it’s Office technology and the platform, and dropping Live from the previous release, M$ has entered private beta testing of Office Communications Server 2007, the software integrates voice over IP (VOIP) calling with traditional phone setups and PBXs.
M$ has also ensured a smooth ride by partnering with Nortel, Alcatel-Lucent, Avaya, Cisco, LG-Nortel, Mitel, NEC Philips Unified Solutions, Polycom, and Siemens to ensure Office Communicator 2007 supports existing desktop phones and TDM or IP-based PBXs. Customers can also use phone software on their PC to make calls without purchasing extra equipment, directly from Office Applications.

Gurdeep Singh Pall, Corporate Vice President of the Unified Communications Group at Microsoft said, “The convergence of telecom and data networks is happening rapidly. Software will integrate these two worlds, enabling IT managers to deliver new communications possibilities that include VoIP. With this open architecture and broad interoperability, Office Communications Server 2007 will give IT managers the flexibility to determine when and how and in what way they move their communications infrastructure forward.”
"Some of the capabilities available in the private beta of Office Communications Server 2007 are placing and receiving voice calls; advanced call routing; streamlined integration with the new unified messaging capabilities in Exchange Server 2007; multi party conferencing; call holding, forwarding and transferring; and compliance capabilities, all while working in concert with existing telephony infrastructure,"