To be fair, the example you showed MM is of the ability of the sensor. Nothing really stops the same sensor being used in a mirrorless camera. And I would hazard a guess that the A7s or one of the other A7 series could do similar/same/better.
But in practice, there probably are photos that a DSLR can do that a mirrorless can't (at this current point in time).
Think 600mm FOV and 800mm FOV wildlife and sports shots. Of course mirrorless can't do these by virtue that lens of these telephoto calibre with AF don't exist in the mirrorless realms yet. We get to see a 300/4 (600mm FOV) in action soon for m43 though.
But more accurately it's not that mirrorless can't do any of this. It's just that currently the keeper rate would be much better with a DSLR rig. When mirrorless AF catchup/exceeds current DSLR, I doubt any wildlife/sports photographer wouldn't make the switch or at least experiment/run dual systems.
Whilst I've seen BIf photos from mirrorless cameras of subjects flying across the frame, I've yet to see one approaching the camera, like an eagle at the moment of striking a prey or something similar with great subject isolation. Again, not saying mirrorless can't do it, but if u shot those subjects right now would u pick any mirrorless system over current DSLR?
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In relation to the earlier post about Samsung, here's some commentary that is relevant:
http://www.sansmirror.com/newsviews/...-distorts.html
Bear in mind Thom is a Nikon guru and no commentary can be considered truly unbiased but I think Thom's usually pretty good. He also uses quite a number of mirrorless systems, m43 moreso, so he does know his way around mirrorless systems pretty well.