Yochay in the team has just released a Windows 7 Sensor and Location .NET Interop Sample onto MSDN. The Sensor and Location .NET Interop Sample Library provides an abstraction of the native Sensor and Location API and provides strongly typed objects for specific sensors to make it easy for .NET developers to support this new platform.
With the Sensor and Location .NET Interop Sample Library, you can create strongly-typed custom sensor objects as well as use the three built-in sensors: Accelerometer3D sensors, Light sensors, and Touch Array sensors. These sensors are part of the Windows 7 Sensor Development kit. This library also provides a unified location API that determines location. With the Location platform, you can use the same APIs regardless of the underlying technology that is providing data, such as GPS, Wi-Fi triangulation, or IP Resolver.
You can download the sample here and you can go to the main MSDN page on this subject here.
Finally there is a great session from the PDC on this subject which you can still find here.