Most cameras now have auto focusing systems and can take multiple shots in succession. The limitation being how fast the successive shots can be taken. I imagine the multiple focus shots could be taken at a lower resolution to speed up capture, and then the algorithm could apply the results to the higher resolution image.

That assumes the technology can be licensed by other manufacturers.

Thats my theory anyway. :)

Some current Canon cameras can have their software replaced with customizeable functions that could do something similar.

The CHDK (Canon Hack Development Kit) is for Canon, but there may be something for other camera makes as well:

http://chdk.wikia.com/wiki/CHDK

With some searching it may be possible now to do this without buying a new camera.