Originally posted by ChristianRock let's see if any pros buy into the thing.
Pros usually have extensive (and expensive) collections of lenses and Sony system would have to offer serious business justification to get their buy-in. I think that mirrorless cameras are simply next step in the evolution, where every step leaves a niche behind, and one of main goals of evolution is to show the image exactly as it is being registered:
TLR got rid of parallax of rangefinder and allowed for observation of depth of field,
SLR did the same, but in smaller body and with interchangeable lenses (among TLRs, only Mamiya C had interchangeable lenses)
mirrorless got rid of complex mechanism of the mirror, again allowing for smaller, lighter and faster bodies.
SImilar story has happened to imaging sensors: as they get better, the sensor, be it a film or an electronic device can be smaller. Again, the progress leaves niche technologies behind, and they are still in use: large and medium (analog) format cameras are good example. Of course the progress is not limited to these aspects: new functionalities like TTL and autofocus are also important, but this is completely different story.