The original posting was about shooting birds, not athletes, a very different thing.
Why? Shooting at the olympics is about getting the picture and publishing it, fast. Bird photography is more about getting the picture.
I'd suggest Nikon has an advantage where image quaility is at premium. But that is the D800/D800E. AF, hihh ISO? I don't have the slightest idea.
Hum... why comment if you don't have the slightest idea?
There are in fact many things in common between shooting athletes and shooting birds:
- you are severely constrained in terms of position relative to your subject which forces you to use long lenses,
- you have very few opportunities to get a shot, success rate is key which points to AF accuracy, speed and reliability, accurate metering,...
- movement is often fast which imposes high speed AF,
- it is difficult to time exactly the positions of the wing of a bird in flight, just like it is difficult to time accurately the positions of the arms of an athelte running or diving, which means that very high frame rates do help increase the chance to get keepers,
- light levels are often pretty low which requires good high ISO image quality,
- the environment in which you shoot is not controlled, which requires ruggedness.
I agree that the need to publish images fast is not there for bird photography, but that's it. The photography part of the equation is extremely similar.
There are of course other differences, like the possibility to add light in sport in some cases,...