A recently filed patent from Microsoft reveals the Kinect is also capable of recognizing sign language:
According to a Kinect patent filed by Microsoft recently, those capable of communicating through American Sign Language standards will be able to input letters, words, and phrases using the imminent technology.More info at Gamespot.
"Where the user is unable to speak, he may be prevented from joining in the voice chat," reads the patent. "Even though he would be able to type input, this may be a laborious and slow process to someone fluent in ASL. Under the present system, he could make ASL gestures to convey his thoughts, which would then be transmitted to the other users for auditory display.
"In this situation, for example, when the user kills another user's character, that victorious, though speechless, user would be able to tell the other user that he had been 'PWNED'. In another embodiment, a user may be able to speak or make the facial motions corresponding to speaking words. The system may then parse those facial motions to determine the user's intended words and process them according to the context under which they were inputted to the system."