Update: the posts referring the AF-S Nikkor 58mm f/1.4G lens were removed from Pixelistes website shortly after my post.
The admin of the French forum Pixelistes mentioned few days ago that he held in his hands a new full frame Nikon lens that will be announced in the next few days. In another post later last week he reported that the new lens will be a Nikkor 58mm f/1.4 that would weigh 385g and will have 9 elements in 6 groups with a 9-blade diaphragm. The price is supposed to be € 1,789 (around $2,400) and shipping should start on October 31th.
I cannot confirm this information but Nikon has filed multiple patents for similar lens and after the release of the Zeiss OTUS 55mm f/1.4 lens, it makes sense to release a new high end 50mm (58mm) lens. The press conference will be tomorrow (Wednesday) at midnight EST (Thursday morning European time).