Hi Perrone, I'll tell you what... when I see a long row of Pro sports shooters at a Superbowl or the Olympics, all shooting insanely high density DX cameras and 70-200's instead of the 400/2.8's, I'll believe everything you just said .
I understand people dream on about always getting smaller and lighter. I'm not convinced DX will really downsize lenses significantly on a sports field because of the noise inherent in deep cropping, among maybe some other reasons.
I could easily be wrong, which is why I said I will believe all this when I see all the 70-200's lined up at the next Superbowl . (meaning the theory of endlessly scaling up resolution really works in the real world and no one will know for sure until that mythical camera is in place).
I can also understand why DX might work for secondary cameras - I was thinking about the main workhorse camera, which I assume now is usually a D3/D4 or some otrher brand equivilent.