How does the (expected) 1D X AF compare to that of, say, a 7D - the vastly increased amount of focus points aside?
The 7D has one f/2.8-sensitive point (the center one), the rest are f/5.6-sensitive. The 1D X has five f/2.8 points and 20 f/4 points. The wider the baseline, the more accurate the AF. I'm sure the AI Servo algorithms are better on the 1D X as well.
Anyway we will see.
We'll see, indeed. In the mean time, it's fun to speculate!
My guess, assuming the 61-pt spec is true: one f/2.8-sensitive dual cross point (the center one), 30 f/5.6-sensitive cross points (the three vertical columns in the center and the inner columns that are f/4 on the 1D X), Zone AF but no Spot AF and no AF Area Expansion, no help from the metering sensor (which will likely be the 63-zone iFCL and not the 100K pixel RGB sensor).
So if this proves true, would you upgrade to this or would this keep you on track to get the 1DX?
I think this question is ultimately asking what type of photographer you are.
That supreme AF specifications of 1D X is simply indispensable for mission-critical photojournalists.
The rumored trim-down AF specifications of the potential 5D successor still seem to be appealing to a lot of wedding/event photographers who want (vs need)
better AF (than 5D II or maybe 7D too) but might
not want to pay a premium for RGB-metering-assisted AF tracking or other advanced AF features/algorithms.