Mr. Maxwell made the statement, "We are very near the limit right now."
Therefore, how "near" is "very near"? That is, when using the current crop of pro-level lenses from the top camera makers on full-frame dslrs, what is the "limit"? Thirty-something mp? Forty-something? Fifty-something? A ballpark number is fine, since an exact number would be useless, and only theoretical, given manufacturing variations, etc.
And I'm speaking, of course, of current silicon, glass and noise-reduction technology- not vapor-ware like negative refraction lenses and other exotic and not-for-sale technology (which I look forward to seeing, but my wallet doesn't )
So, any engineers, or armchair engineers care to take a crack at it?