Interesting Panasonic sensor patent: on-sensor ND grad "filter"

I was thinking about ND grad filters: one day could this be built-in to the sensor?  If it was possible for each row of pixels on the image sensor to have a very slightly different ISO sensitivity the sensor could provide a very flexible ND grad functionality.  The user could tweak hard/soft graduation, choose filter density, "horizon" position, etc.

Before I rush to the patent office... turns out Panasonic beat me to it! 

http://www.43rumors.com/panasonic-patent-shows-describes-a-new-sensor-tech/

I thought this was an interesting idea.  Who knows, it could one day make it onto a new generation of MFT sensors.