while is for sure an interesting development, earth shattering it is not. The prelude to the demise of the dslr market, it is not. If mirrorless can get off the ground and run, if people buy into it at this price then we will see interesting developments. But, markets are weird - and the camera market is especially weird nowadays (screw mirrorless, and FF, and anything that isn't a cell phone - many say the whole upper end of the camera market will crumble because consumers are more and more opting out of having a stand alone camera at all because their cell phone is right there - so the race for quality may be lost for the bulk of the market in favor of ease of use and networking. Yes, any slr with wifi now can be run with the cell phone, and images can easily be shared via social networks...but that's like 3 steps more than just snapping the shot with the cell phone - which is what the vast majority want.
With a consumer market increasingly ditching cameras for cell phones, this widens the gap in IQ which I think will make life a little easier for pros. But, not easy for a mirrorless system like this. I think Sony may have put the cart before the horse here. The A7 and A7r do on paper look impressive, but without more glass it will be a hard sell. And as many pointed out, while its a FF sensor, there are many little known things that suck about it (battery life of up to 300 shots...SD cards...), and the unknown - how does the EVF perform? I have toyed with a sony mirrorless and an olympus -- the olympus EVF wasn't as bad as the sony, you could tell it was an electronic translation of the world though - while the sony - I really did not like looking through the EVF, maybe it was because it was lower light, but there was a huge delay in what was seen vs what was happening - which says to me ---- mirrorless is a long way from taking over the market!