Why doesn't Nikon use 2 processors to achieve higher fps?

^^^ This

It wouldn't matter how many times a second it happened, the mirror up/down and the shutter speed is the same each time, whether it's once a second or X times a second.

Yep.

Nikon's strategy is curious. I'm not sure we're going to see a D750, but it certainly wouldn't be hard to do.

I am curious as to how many people would buy the following, assuming body build (feature set) stays as it currently is but the price slides a little with the different sensors:

• D600 @ 16 vs D600 @ 24
  
• D600 @ 24 vs D800 @ 24
  
• D800 @ 24 vs D800e @36

I guess I'm most curious if the feature set or the sensor would be the driving factor if all else was equal. I think a lot of sensible people know they don't need 36 MPs but most definitely would like the very best in AF, metering, etc.  Personally I think Nikon should have had two 24 MP bodies and one 36 MP body instead of the other way around.