We couldn't get a word out of Sony regarding their motion controller other than it tracked light in 3D space and would not unseat the Dual Shock as the primary PS3 controller. But Sony recently told developers a bit more.
Broken by Kotaku, Sony met with developers to better explain their motion controller follow E3. Here's what was passed along:
• Spring 2010 release schedule (still no price)
• Four motion controllers can be tracked at one time
• The PlayStation Eye will support voice input/recognition, face/head tracking
• Sony would like to combine motion controller and Dual Shock gameplay
• Motion control sucks some PS3 horsepower, so developers will need to accommodate it
While Sony has been developing all the aforementioned technologies for some time, we can't help but see a few capabilities pointed out here—voice/facial recognition/tracking—that were neglected in Sony's E3 presentation. Is it possible that the positive response to Natal has made Sony reassess which components of their system are most marketable to developers? Yeah, it's possible. [Kotaku]