Reviving a very old thread but it looks like the idea behind my initial proposal might be coming to fruition in 2017.
Ok, so the D810 successor's not out yet but the rumours put it in the 46MP+ category.
Now Nikon's also released the 28/1.4E which looks to be superb and every bit the match for a high resolution camera.
So updating for 2017, we might get:

46MP FF @ 28mm f1.4
27MP APS-H @ 36mm f1.8 DOF FF equiv
20MP APS-C @ 42mm f2.1 DOF FF equiv
11.5MP m43 @ 56mm f2.8 DOF FF equiv

That's a lot of wide-normal FOV coverage whilst retaining good resolution even with cropping.
Bad news is the potential cost of such a setup LOL.