I went to a talk recently about birds of prey, and in it he had a model of a raptor eyeball. Unfortunately I can't find a picture online to show you, but the interesting thing was that the back of the eyeball had something like twice the surface area of the front. Imagine a truncated cone, with the top smaller part being the front eyeball and the base being the back, to give you an idea. The lecturer talked about how the reason for that was that they could pack so many more rods and cones on that eye, which the birds used to see prey from 3000 feet up. What he was talking about was evolutionary zoom.
Of course I related this to cameras. Whenever a rumor comes in for a big pixel camera somebody lectures us on how unnecessary that is, it would just clog our disks, and so forth. But with more pixels you can crop and zoom and still keep detail. With enough pixels, and a high enough resolution 50mm lens I can see a case where lugging around a lot of zooms diminishes.
Anyhow an improved autofocus from my 5DMKII, such as in the 5DMKIII is all I really need, but I'm hoping they do release a big megapixel camera, preferably in a 1D body. I'd buy it.