Source? According to wikipedia "As of June 2011, it is not yet known to have been ratified by any standards body, and the extent of work by Apple with regard to this promise is unclear as Apple has not released technical specifications for the service. FaceTime is not currently supported on any non-Apple devices.
While FaceTime is based on open standards, Apple's FaceTime service requires a client-side certificate. In other words, while the protocol might become an "open standard", access to Apple's FaceTime service is controlled by Apple.". This means that encryption keys are owned by Apple, and not by users.
