Just guessing here, since I haven't seen one torn down, but when I first saw the drawing of the sensor I assumed there would have to be some sort of modification to the end of the handlebar. We already know the grips change to match up internally with the gear on the end of the sensor and to eliminate the connections for the cables. I can see two things that would need to change on the bars:
1. A notch for the sensor to lock into, to prevent the entire sensor from rotating within the bar.
2. Shortening the throttle end of the bar to allow for the "gear" mechanism on the end of the sensor (to keep both grips the same distance from the centerline of the bars).
IF they made the sensor to fit within a standard diameter handlebar, it may just be possible to modify existing bars to make the system work by grinding the appropriate notch for antirotation and sawing off the appropriate amount to equalize left and right. Of course, we won't know for sure until some brave soul takes his new bike apart to scope out how all this really fits together. Any volunteers???
Jerry