I doubt Google has anything to do with the hardware for this. Qualcomm has been pushing movement tracking and user context recognition using sensors with their

I doubt Google has anything to do with the hardware for this. Qualcomm has been pushing movement tracking and user context recognition using sensors with their chips without using a lot of power at conferences for over a year now. This is probably just Google throwing in a cut down version of their Pivot functionality. It's basically a chipset feature, just like how the chipsets are who pushes the OpenGL ES drivers and demos each version.