Does kinda makes ya wonder. Those are totally professional, commercial-type cameras best used for oversize enlargements. With our current printing/processing technologies anything more is going to be overkill. Even at that, you can do quite well with the pro-sumer cameras such as the Nikons and Canons at 4-6.5mp in a professional environment and not be embarrased by lack of quality photographs. Most sports folks shooting digital use the Canon 1D at 4mp.
For consumers producing the standard 4x5 to 8x10's and yes, sometimes better at 11x14's or so, you can do very well with a 4-5mp camera. The nice thing about the D100's, D60's etc is that you can use professional 35mm lenses on them.