Egami blog published a number of recent Nikon patent applications. One of them places small microlenses in corners between the big ones to reduce an optical crosstalk:
Another application, also quoted by New Camera site, proposes an HDR sensor with big and small pixels with big and small Bayer filter patterns:
Another application, also quoted by New Camera site, proposes an HDR sensor with big and small pixels with big and small Bayer filter patterns: