Gingerbread will have support for a lot more sensors which will prove very useful for stuff like: user interface, augmented reality, gaming, image stabilization, and navigation. They are bringing together the accelerometer, gyroscope and magnetometer data, which will make it a lot easier for developers to code apps without having to worry about coding for each one separately.
InvenSense, the company behind this sensor technology has been working on this for quite a while. They are also the ones to bring this technology in Nintendo's Wii remotes. They even gave a nice talk and showed some demos back in August, at a Google Tech conference. Watch it in the video below: