I think the Df is the answer for guy (like me), who are tired of paying additional premiums for new cameras that have video incorporated, even if I/they have no interest in doing video. I'm a Canon guy, and I'd dearly love a 1Dx WITHOUT video. The so-called melding of still and video is, I believe, overhyped. Sure, many pro photographers may have a secret hankering to be the next great film director, but at this stage, I'm not one. (I actually started my semi-professional life more than 30-years ago as a cinematographer and morphed into still -- and was happier. I even won an Honorable Mention in Kodak's Amateur Film contest many, many moons ago.)
I think there's a strong market out there for still, and still only. Kudos to Nikon.
Nemo