Kinect may be used on Windows Phone 8

Rumors have sprung up claiming that Windows Phone 8, also known as Apollo, could use Kinect's technology to grant users new interface options.
Kinect is Microsoft's hands-free interface solution, which was introduced as a gaming peripheral for the Xbox 360. Microsoft has also implemented the device into Windows 7.

January rumors claimed that Asus is producing prototype Windows 8 laptops with Kinect's Natural Use Interface (NUI) built-in, and Kinect functionality would be integrated into more portable hardware in the near future.
There's not enough space

Just how exactly the stationary Kinect could fit (or even work) in the phone is of interest, and Microsoft's R&D department is reportedly having trouble squeezing all the components of Kinect into a phone. Kinect uses three cameras, one of which is infrared, to detect the body's movements for gesture-based control interfaces.
The infrared camera is essential for use in dark environments, and without it, the NUI features would only be usable in daylight-like conditions.
Microsoft supposedly outed several new Windows Phone 8 designs in February, including small tablet-sized devices that would much better fit Kinect's various elements. But gesture controls aren't the only feature Kinect would bring to Windows Phone 8.
Sticking it to Siri

Kinect's also a boon with voice control capability, something a Windows Phone could take advantage of to compete with Apple's Siri. Response to Siri has been positive, though Microsoft's own TellMe voice recognition service is said to be even better at interpreting your commands.
The Kinect NUI will be tied closely to the TellMe service, the rumors say.
Other sources claim Sony will release their own gesture- and voice-enabled phone, running on Google's Android OS, within a year and a half at the latest.
Windows Phone camera to detect motion

Similar controls were originally meant to be implemented in previous versions of the Windows Phone OS, but were scrapped for unknown reasons.
"It will use the camera on the phone to detect motions and create appropriate actions," Microsoft said previously.

"You will be able to shake, twist and otherwise manipulate the phone and get things done. The phone will be able to perform actions when placed face down on a surface, and it will know when it is in your pocket or bag."

Those plans were scrapped some time ago, but Kinect could pick up the torch exactly where it lies.