I have 3 Cameras, one with DPAF, which is nearly all I could could want in a DSLR vs. Video Cam. I have 8 lenses, ALL EF mount, albeit ef or ef-s. I have zero issues with a mirror, nor have I since 1974 when I bought my first Canon camera. I do not see why this whole "rush" to mirrorless even exists. Weight? New Technology?
Competition?
I have made a living using my Canon 35mm, then on to EOS AF Digital. You can create all the newness you want, I am never going to give it all up. I walk around Watkins Glen this summer at the 6 hour endurance race. There were more folks with Canon than all the rest added together. There were as many "big whites" as who knows. Why give up something that works.
Many have said, the best camera is the one in your hands. I see zero reasons, regardless of the technology, competition or future, to empty my backpack of those three cameras and 8 lenses for anything, and spend 10-50k on starting over.
Canon... all I wish for is more lenses that are lighter, and clean HDMI on everything. My only dreams are to able to carry more on my shoulder or in my hands, with attached monopods, and the ability to record video externally on some other devices.