If you have been wondering about how to support your sensor or location device on Windows 7, wonder no longer! The Windows 7 Sensor WDK documentation is live on MSDN:
This documention covers driver development concepts including coverage of the two interfaces of interest:
ISensorClassExtension (Docs HERE)
This is the interface for the root Co-Creatable object that sensor drivers use for outgoing calls (Initialization, posting events, etc).
ISensorDriver (Docs HERE)
This is the interface that sensor drivers implement as a callback to handle incoming calls. Requests for property data and sensor data are serviced on this callback interface.
That's enough to get you started!