What does system resolution tell us about sensor trends?

Using the formula that Marianne's speculation seems to confirm - Rsystem^2=1/(1/Rlens^2 + 1/Rsensor^2) - I get the 85mm f1.4 G to have a resolution (MTF50) of 205 lp/mm on a perfect sensor. The numbers by format/MP (all else being equal) work out like this:

DX 12MP - 164; 16MP - 172; 24MP - 182

FX 12MP - 134; 16MP - 145; 24MP - 159; 36MP - 170

My guess is that the megapixel race is all but over. In DX 24MP will deliver about 90% of the potential resolution from an excellent lens; FX will reach that point at 54MP.

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Jim