In 2018 Nikon will launch their first Full Frame mirrorless system camera(s). It will be the first real competitor of the Sony FE system. And to make a splash it seems like they are working on launching very fast primes lenses.
The Japanese website Hi Lows Note spotted the patent of a new 50mm f/0.9 and 35mm f/1.2 lens. There are no such Sony FE lenses yet and for sure this would help Nikon to get some “attention” from photographers. So my take for Sony…beat them and make such lenses too :)