I think 3 types of pro bodies make sense. 1) high res, 2) high speed and 3) high DR
I don't see a reason why you can't mix your options #2 and #3 in one bottle. You can use the same generation of sensor to have high speed / high DR / good ISO performance in one camera (such as 1D X) and high res in another (rumored Nikon D800 as an example).
So there could be:
1D X for pros (12fps, 18MP)
5D X for pros, semi-pros and amateurs (same sensor as 1D X, but much lower fps, say 4 - 5 fps)
5D S for pros, semi-pros and amateurs also (new sensor with 30+ MP).
X series adresses wildlife, sports and so on.
S series adresses studio, landscape, architecture, macro and so on.
Too bad for me, I'm on wildlife, landscape and macro, so I have to buy both 5D X and 5D S, though can afford none of them
@nightbreath: nice website, like the style of your photos.