Just wait until Nikon enters the mirrorless arena...
Gone is the heavy pentaprism...
Once a decent lens, with good elements and well built, is on, the pentaprism is a minor weight. By decent lens / weight I do not mean telephoto. Just means decent lens.
Gone is the flapping mirror...
Yes, that is an advantage to have it gone. Fair. Less moving parts, less to go wrong vs solid state.
Gone is the unreliable focus module, needing adjustment now an then...
I have a D4 and D610, no issues focusing at all, focusing either. Not sure why some do have issues.
Only if the manufacturers stop making them.
For cost reasons, they will, as EVFs become cheaper.
Still understand the DSLR affectionionados fearing the days of glory slipping away...
Nothing to do with glory days, times change. Most interested in ML and not yet purchased and using Nikon and Canon DSLR's were just waiting for their brand to start making them.
Nikon make a substantially better camera than Sony.
Much better weather sealing for example, which is critical to many.
In the meantime, the DSLR's will do fine and will be used even when ML are released, until they wear out.
And even when ML come out, many will be hunting used DSLR's which still work great, such as used D4's , D80OE's, D810's.
I have no intention of getting rid of my D4. Got it recently for a third of original retail price.
Will still be a better camera than a USD3,000 ML, even a Nikon one.
Because it was better made in the first place.