The Device APIs Working Group has published two Working Drafts today:
Ambient Light Events: The DeviceLightEvent interface provides information about the ambient light levels, as detected by the device’s light detector, in terms of lux units. This specification defines a means to receive events that correspond to a light sensor detecting the presence of a light.
Proximity Events: The DeviceProximityEvent interface provides web developers information about the distance between the hosting device and a nearby object. This specification defines a means to receive events that correspond to a proximity sensor detecting the presence of a physical object.