Another way to increase dynamic range is to make two exposures, one for the highlights and another for the shadows, then combine the digital images offline. GLuijk has discussed this technique exhaustively in the "zero noise" thread.
This technique could be implemented in the camera with no extra electronics. For example, the user presses the shutter button, set say to 1/125 sec, the camera acquires a 12-bit image at 1/125 sec for the highlights, then aquires another 12-bit image at 1/8 sec for the shadows, then merges the two images into a 16-bit final output.
As this example shows, the technique would work best for fairly static subjects with a tripod mounted camera, since the exposure for the shadows would tend to be long, but the technology for this is here today, and it would extend the dynamic range of any sensor as much as desired.