I think it’s unlikely that Nikon will go with a 1.1x format. Their approach to date has been to standardize with the 1.5x DX format.
I think there’s room for a FF in Nikon’s lineup, but I don’t think DX is dead. The technology will contiunue to improve, the cost of FF will drop, and the image quality that can be had from a DX sized sensor will get better – and not necessarily due to more pixels. (Think noise, dynamic range, high and low ISO).
While it’s fun to speculate, and there’s certainly no shortage of it on the internet, we really won’t know until we know. If Nikon is true to form, whatever’s next will be killer, and fit nicely in between their main competitor’s offerings.