Windows Phone 7 might get VoIP support and video calls
Microsoft is working on a competitor to the Apple iPhone’s “Facetime” product, a feature of the platform that allows the user to make video phone calls to other users of the iPhone. Microsoft seems to be using Voice over IP technologies (VoIP), and the functionality is already built into the platform, further supporting the claims that the company is working on such a features. You can view the registry keys hidden inside Windows Phone 7 registry that describe the features. The registry keys “VoIP” and “SIP” are hidden inside the “ControlPanel” portion of the registry, and both seem to be set to be off (by having “0” under their “Enabled” value).