According to a recent patent filing, Sony is working on a modular motion controller. Dubbed the "hybrid separable motion controller" in the filing, the controller is essentially a fusion of the Dualshock controller and the PS Move motion sensor.
Diagrams indicate that the controller can be played like a regular controller, broken apart to play motion-enabled portions of games, and then recombined again.
The patent also indicates that both sides of the controller will be equipped with an accelerometer, speaker, magnetometer, and gyroscope for motion detection.
Unfortunately, the patent reveals little of the plans that Sony has for this motion controller, although presumably this new motion controller may be the first of many plans that we see for the next-generation PlayStation as we move into 2013.
You can see the patent filing for yourself here.