I keep hearing mirrorless. Does anyone want a mirrorless camera like that? Why would yu spend that kind of money on a mirrorless camera? What pro wants to be looking through the LCD?
I don't mean this in an insulting way, but why would canon make a billion dollar mirrorless?
The Single Lens Reflex was the solution to the viewfinder problem in interchangeable lens FILM cameras. The only reason it sticks around is a combination of tradition and conservatism. It is a solution to a rapidly vanishing problem.
Remember that before the SLR, the vast majority of interchangeable lens cameras were viewfinder types. The viewfinder was good for only one focal length; once you changed lenses, either you needed a separate viewfinder or a corrective optic that you looked through. Both solutions were unsatisfactory (and suffered from parallax), but it was all we had before the SLR. The only other styles were of course the view camera (where the SLR idea came from I imagine) and the TLR (where you had two lenses, and hence twice the cost).
Today, there is no need to look through the lens when the sensor can provide a perfect view to an electronic viewfinder.
You might still want a shutter curtain (doing it electronically isn't always the best answer), but there is no reason that a shutter couldn't still be there, it would just reverse the operation. Push the capture button and the curtain closes, then reopens to see the view again.
I for one would consider a FF mirrorless to replace my 5D3 in due course, provided it has all the same capabilities (particularly the high ISO and frame rate).
