Camera Labs has published a quick comparison of shots between the Nikon D800 (the non-E version) and the beastly Phase One IQ160 60MP. I would have preferred a comparison with the Pentax 645D, since it is the closest in both resolution and price. While we can go to DPReview and use their comparison tool, any good photog knows that the studio shots that are conducive to standardized testing are rarely a good measure of a camera's real-world resolution abilities. That's what makes side-by-side, landscape comparisons like this so useful.
Regardless, it is a foregone conclusion that the Phase One out-resolves the Nikon. In some cases, by a noticeable margin. Unfortunately, the lens choice on the Nikon is not Nikon's sharpest lens. A good prime would have been a better choice. Still, as is mentioned in the article, the difference cannot be wholly attributed to the lens — the Phase One is resolving an amazing level of detail. I think a more interesting choice would have been the Nikon D800E since, without the AA filter, it is more architecturally similar to the P1.
One thing that I took from the comparison is that the medium format companies will have to bring their A-game yet again. I remember writing years ago that I thought medium format was a pointless purchase. Phase One then came out with a back that had more than double the resolution of FF cameras at the time, and I was made a believer (a believer that could never afford one, but a believer nonetheless). Now, the FF crew has stepped up their game and closed the gap between them at MF to such a degree to again make the massive price premium, to my eye, not worth it. The 80MP IQ180 is still in a class of its own, and if you need it, you need it. But every step down from that makes the D800 loom ever larger. Perhaps its because back then, the numbers were so small as to make any jump immediately noticeable. The jump from 36 to 60 is smaller than the numbers make it appear.
But likewise, at numbers this high, the correct comparison can reveal a camera's true abilities, and that may not be happening here. A studio model, or a more complex landscape may provide the images that "pop" in the same way that the mountains in the upper-left of Camera Labs' test pop in the Phase One's image. It's very impressive.