I would prefer to stay away from further increases in pixel count since I have no practical use for the additional information and it would increase needs to storage and computational resources. I'm very happy to have a camera now which can mostly handle the focusing requirements of its sensor (D5) even at wide apertures and a computer which makes it practical to edit those files without waiting. A D810 NEF converted to TIFF and edited normally (two additional layers) is about 600MB on the disk. Going to 96MP would push that to 1.6 GB per image. Most such images would likely be slightly out of focus because of this I can't see how there would be perceptible gain on image quality at least in my own applications. A much larger sensor size (such as 6x4,5cm full frame or bigger) would make sense if you need such resolutions and I would imagine the benefits would be much more tangible.
I like the D810 body a lot and would like to get the Multi-CAM 20k and Nikon's radio flash control added to it, as well as XQD card support (maybe SD UHS-II in the second card, though I would prefer two XQD, since SD UHS-II seem just as expensive as XQD but more fragile, and I don't want to invest in a huge variety of expensive high speed cards that are incompatible with each other). Canon has the sense to put a practical resolution (30MP) in their mainline 5D Mark IV (they usually have the pulse on what most photographers need; shouldn't be surprising that their market share is increasing even though they're already no 1). If Nikon wants to make an ultra high resolution variant, by all means, as long as other customers who specifically don't want it are given reasonable options to choose from as well.
