The question is not only about resolution but also MTF, and than we would need add sharpening to the equation.
Yes, I was rather loosely using "resolution" as shorthand to cover things like "MTF as a given lp/mm, or a given lp/ph".
We also need to keep in mind that we may have different croppings. A square image on the D800 would be 24 MP.
And more relevant, a crop to 4:3 shape would be 32x24mm and 32MP.
Another thought: the D800E pixel size is not that much smaller than in the 80MP backs:
- The 80MP sensor is 10328 x 7760 over 53.7x40.4mm, so 5.2 micron pixel spacing, or 192 pixel per mm, so with Nyquist limit 96 lp/mm.
- The D800(E) sensor is 7,360 x 4,912 over 35.9x24mm, so 4.9 micron pixel spacing, or 205 pixel per mm, so with Nyquist limit 102 lp/mm.
So with the overall trend (based on fundamental optical factors like spherical aberration) being that good lenses for smaller formats have better resolution in the sense of higher MTF at equal lp/mm (larger formats win at equal line pairs per picture height, by having more picture height) the fact that MF lens systems are keeping up with 80MP backs suggests that 35mm lens systems should likewise be able to keep up with the D800(E) sensor.
Also, as I have mentioned before, fine grained black and white films like TMAX 100 still out-resolve any of these sensors, and I have never heard either 35mm or MF users commenting that the resolution of such films is useless because lenses are inadequate, so why should this be the case with sensors? Especially when one allows that Bayer demosaicing reduces the resolution somewhat, so lenses with good MTF up to about 80lp/mm should be able to keep up with these sensor just fine.
(TMAX 100 has MTF of 70% or better out to about 100lp/mm, at or beyond the Nyquist limit of any of these sensors, and has MTF of 50% or better out to 125lp/mm, the Nyquist limit for the 24MP "APS-C" Sony/Nikon sensors. We are still "not there yet" in terms of DSLR sensors out-resolving all