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

Class D amps can sound good, you just have to put a tube dac and tube preamp in front of them.

OP. What amp? What loudspeakers? what source? Give us a chance to see where you are? 

I sure like mine in the summer TIME and doing bass duty ALL the time. Dropped my temp and PG&E trying to stay cool and listen to music when it's 110 degrees outside. I'm crawlin' into the bunker just to cool off. 

The older I get the LESS I like the heat or below 30 degrees..

12 full degrees cooler in my front room from Valves to Class Ds AND 1/3 the AC cost.. Fall, Winter or Spring is whole different thing.. Valves ALL the way.. Still class D amps doing the heavy lifting in MB columns and A/B step baffle servo bass amps (Rythmic plate amps) & GRs drivers.

Point to point on the Tape/Phono. Heck I use EVERYTHING..

First Watt Active XO, pretty serious step baffle set up, CLASS Ds just sound wonderful through it.. (For Elixirs monitor section) Wima caps.. God bless um.. BOTH are just full!!.. Nelson Pass and Wima have a romance going on.. I'm tellin' ya.. Good caps too..

Regards

As others have said, class D is now quite good, and for the majority of users it probably delivers the best value when taking into account sound quality, size, heat, weight, etc. I've got a pair of DIY Purifi monoblocks that sound excellent. 

But, I recently acquired a pair of Pass XA60.8 monoblocks, and there is something about the sound that is captivating beyond what the class D amps can deliver. I'm sure there are tube-fans that would say the same about their amps. 

I don't think my Pass amps are any cleaner, more dynamic, or more detailed than my class D amps, so there is something else that is influencing my satisfaction. Perhaps it's minor tonal changes, or distortion harmonics, or maybe I just like a slightly warmer room :). 

But whatever the reason, I think there will continue to be different options to produce different sonic signatures, since everyone's perception of reproduced music, and preferences, are a little different. 

I do think class D will eventually dominate as the value leader, but there will always be audiophiles that have enough money to buy what most appeals. This may shrink the market enough that there are fewer choices, but I don't think they will go away any time soon. 

I have had some good class D ,I still feel a very good class A, AB 
sounds more fluid .I hav3 a Coda CSIB integrated  and it has much more. Control ,and depth of performance IMO. Spotted 3,000kva transformer ,and over 80k uf in capacitance  runs in pure class A for almost 20 - 1st watts and pure class A preamp ,even my dac runs in pure class A on the analog outputs  I am good with my Amplification I think it just has more depth, some class D like Merrill sound very good but Waay over priced ?