I already sold my 5D Mark 3 and got a Sony A7 and Samsung NX1, which both fit my needs exceedingly well.
These 50mp Canons are definitely for landscape shooters, and possibly certain studio fashion photographers, (although I, being one of the latter) don't need more than 30mp.
For me, the Sony dynamic range, and Samsung color + rendering are utterly phenomenal.
I still prefer Canon colors over Sony colors, but being able to shoot with a mirrorless system with all its benefits of live view and functionality- I can never go back to a mirror system.
DSLRs will soon become a niche for sports and wildlife who need to "snipe" their targets. But even then, mirrorless evf technology has its pros for that too.
Lastly, I sold my 50L, 35L, 100L, and flash system, but I'm still thinking about holding on to my 24-70L II for the rest of the year. To at least try out any new canon products.