Expanding its existing Skype for Business dashboard, Skype for Asterisk, the latest capability called Skype for SIP, is a new service that allows Skype users to communicate with any SIP-supported enterprise extension.

The application writeup in NetworkWorld really lacked an realistic usecase. 

My view of the implementation is that the service allows Skype to be the softphone for the enterprise to complement the company's relationship with VoSky and their Skype gateway which is an intra-enterprise gateway. The channel for the service may in fact be enterprise PBX and IP PBX resellers.