Is the FX revolution fizzling?

I respectfully disagree.  Let's define a "Pro" body first.  Must it have magnesium frame & weather resistance?  Probably, but not absolutely necessary. Full, ergonomic control of exposure functions, focus choices, shutter, recording functions, etc . Absolutely.  Should it have high frame rate and long life shutter?  Yup.  Absolute best in class AF?  Without question.

Nikon already makes a body like this.  How much R&D would it take to place a modern sensor & upgraded processor in this body?

Next question.  How many DX users with 2 or 3 DX lenses would be tempted to spend $1700 dollars to get a "Pro" camera with performance that blows their low end/mid range camera away without the need to spend a lot more for the lenses which FX requires?

A DX camera like this can do  just about ANYTHING, unlike a D600.  OK, the DOF is a little thinner with FX.  But, DX is wider!    OK, the ultimate print size is larger and you can crop a little more.  DX has more reach for each focal length. FX has wider field of view.   FX has, perhaps, a stop more low ISO, a slightly higher dynamic range and less high ISO noise.  With today's technology, those advantages are getting narrower and losing relevance because DX and m4/3 sensors are getting so good. Comme ci comma ca.

I do not think "the vast majority of the market" would necessarily choose a D600 for more money.  Some would.  Some have...... because there hasn't BEEN a Nikon alternative as we've described.  Wait till there is!  I'm waiting.

Respectfully,

--
Warren