Class D amps seem poised to take over. Then what?

Class D will most likely take over if you have inefficient speakers that take tons of power like Electrostatics.  They are great in large areas, sub woofers because they are powerful.  I have heard some class D amps and they do sound good.  For some people probably a good choice depending on the room, speakers, tastes in music. 
Most people probably wont notice much difference.  Not if you have really good Speakers that bring out the best and the worst in music with a side by side comparison.  From that point it is what you like to hear.
My notion for class D got soured badly when I made my first exciting investment with a combo Integrated class D amplifier, streamer. It was small, cute,  powerful. It was dynamic. I was using 45 year old Crown A-AB+ 90WPC Amp, Crown Pre Amp. 
The line that crosses between a good system and a high end system which varies greatly depending on what it is and the investment.
I was getting ready for that old equipment to have a good butt whipping!  Uh, No, not even a close comparison.  Where the Old Amps were getting the details, Low Dynamics in the Trombone, Tuba crescendos giving balls to the lows, the Class D failed to reproduce any hint of fullness of the true tones of the instruments. Only Bass, sharp toned highs. Could have been a mismatch of my titanium drivers. I have 8" carbon fiber woofers. There was plenty of power from the 60W class D.  In fact it had more loudness that the old 90W unit and the class D driving the woofers hard.  Just the details I look for in music were not there.

Then, I decided to go get the best I could afford.  I went with a Tube integrated and it is in a league of its own compared with the Crown.  Crown was good, but nothing like the Tube integrated at half the power. I have learned from a friend that bought a pair of Red Dragon mono blocks.  He said they were very good, but the Shiit Vidars in mono sounded better on his Magnapans. I will never give up my tube integrated until I am in the grave. I have had it 6 months and it just keeps sounding better. Jaw dropping sound, detail, enough to make you laugh, cry, and dance with the wife.  :)
 

Class D amps have gotten better without doubt. They are performing on a level never thought achievable. But as good as they are in providing great transparency, detail, full midrange (vocals) and deep mind-blowing bass they still fall short in delivering the emotional aspect of the music. Not tapping my foot anymore. Fix that and I might consider retiring my Class A/B amp.

The SQ of my current Class D amp is the most emotional I have experienced without any other even coming close.
Maybe it’s the lack of distortion, having the right harmonic distortion, the transparency, the smoothness, the sweetness or the sheer musicality. To just say the sound is “wet” and not at all “dry” is an understatement.
I have certainly raved enough about my particular Class D amp.
But now feel there are, at least, a handful of Cl D amps on the market which have similar qualities.
I believe that within this decade Class D will surpass all other class amps and become the “benchmark” of quality Audio amplification.

Or it is just validation in your mind.
Not saying that as a disparaging comment I felt the same way with a couple of Class D amps till they showed their true nature.
I decided Class D is great for out on the deck, cheap and do not care if it gets wet.
Like what you like and be satisfied. If you are coming here for validation good luck with that.
Dead bodies attract dead bodies.