Olympus uses the term "PRO" to distinguish its weather sealed cameras/lenses, but then some of it's non-weather sealed lenses are of highest quality (e.g. the 75mm f/1.8). In addition, the E-M5 Mk II in high resolution mode is quite comparable to high resolution 36mm sensors when used in the studio with good light. These are each pushing the limits of older lenses.

As far as what is used for professional photography...there is what works, and what is needed for a "professional image". These days, anyone can have a high resolution 36mm sensor; so for a "professional image" you should go big (by which I mean medium format). As a bonus you get leaf shutters in your lenses.

The new Olympus is getting more pixels, less noise, better focus (looks like much better), faster burst mode with buffers to support it, high resolution mode, and lots more. It's less of an upgrade than a leap. Quite a package, which hopefully means I can take a lighter kit instead of my Nikon gear...but it still doesn't replace it for all uses.

For the same reason the manufactures kept raising pixels in most cameras years ago. A few years from now, at the pace manufactures are going, professional cameras will have a burst mode of 25 fps. Another example is, look at the iso rate of your high end cameras...when will it end? As long as consumers think "MORE IS BETTER", manufactures will keep producing cameras this way. The only point I'm making is....if an action photographer can't pick out a good shot at 10 fps...theres something wrong.

For the same reason the manufactures kept raising pixels in most cameras years ago. A few years from now, at the pace manufactures are going, professional cameras will have a burst mode of 25 fps. Another example is, look at the iso rate of your high end cameras...when will it end? As long as consumers think "MORE IS BETTER", manufactures will keep producing cameras this way. The only point I'm making is....if an action photographer can't pick out a good shot at 10 fps...theres something wrong.