A need to make call using SIP or DDI or Incoming numbers?
B need to receive call using SIP?
C need to receive call using SIP?

N.B: that means, integration of Skype inside FreeSwitch, doesn't make Skype Client software's available? Like as said, to get something you lose something!!

ex: skype for mobile we have to stop dreaming, and build our own sip application for mobile?
ex: skype for device we have to stop dreaming, and build our own sip application for device?