Irwin Lazar in response to my previous post about Cisco versus Microsoft writes

Many of the enterprises I speak with are wondering the same thing. For the last few years Cisco has arguably owned corporate “mindshare” when it comes to VoIP. As Microsoft rolls forward with its plans, the question is not just where does this Cisco, but all other VoIP systems vendors as well. Will VoIP phones just become a subset of a greater communications infrastructure, with features being controlled by a client embedded into business and office applications? Or will there still be an opportunity for phone system vendors to introduce phone-based features.

Irwin says that for near foreseeable future, Microsoft is going to be indulging in co-opitition” with its rivals and will be forced to work with them, primarily because in the end enterprise is still a buyers market.