If not, why not? Many cameras adapt to motion by increasing the frame rate, why not change the shutter speed/gain?
1. Enable camera to capture scene without bluring during periods of quick motion. (Person running towards a entrance)
2. Enable camera to capture scence with enhanced detail/reduced artifact during more static scenes. (Same person pausing at a an entrance)
3. Reduce nighttime noise/bandwith by using less gain unless "real" motion is detected.
4. Make motion detection at night more usable because of less false positives.
Is the problem that you can't change the exposure settings of camera quickly enough, i.e. between frames? Or that the transition frame(s) would be somehow artifacted and unusable? Maybe the switching back and forth could be too quick, and would certainly bloat the H.264 stream during those transitions. Maybe a dual MJPEG stream and H.264 stream with different exposure settings for each? Does that exist?