Nikon and Tamron filed a joint patent application in Japan for a 200-500mm f/4.5-5.6 lens. Nikon has already filed for 200-500mm f/3.5-5.6 and 200-500mm f/4-5.6 patents in the past. Tamron recently released a new SP 150-600mm f/5-6.3 Di VC USD lens, while Nikon has their 200-400mm f/4G ED VR II model.
Nikon also recently filed a patent for a honeycomb sensor with sub-pixels in between – this design should improve the dynamic range:
