Well, as has been said here, when the mirrorless system can actually replace the DSLR in every situation, then the DSLR will be a thing of the past, and in my own view, that will be fine.
But I think the current general crop of mirrorless are targeting the biggest sales, hobbyist, amateur, general condition shooting.
I don't see any mirrorless system currently and for a decade to come that even remotely looks as though it can/will replace the Canon 1Dx II or the Nikon D5.
My Sony RX1R is an absolutely great little Camera, but it's horses for courses, general shooting, inconspicuous street photography etc.
When I finally receive my Hasselblad X1D I have no doubt it will be a wonderful Camera, for certain conditions, it may replace in many situations my 5DsR, but even the X1D will have it's limits and they can be reached pretty quickly, like most cameras.
I think the DSLR is going to be around for another 20 years or so, no need to panic just yet.