Analog 2Ch Preamps will never become "obsolete" for sure.
But I think that even with MCH Pre-pros these days, the A/V Tech is advanced enough that I don't think they will become obsolete any time soon.
For most people (TV size and distance), I think 1080p is about as good as it gets (of course, not all 1080p are created equal).
And for Discrete MCH, I think DTS-HD MA and Dolby TrueHD Lossless audio is as good as it gets. They can add a million surround speakers all they want. But the salient speakers will still be the front 3 speakers and subwoofers.
Unless they completely do away with HDMI, I don't see these Pre-pros with HDMI, 1080p, DTS-HD MA, and Dolby TrueHD becoming obsolete any time soon.
I think most everything else is just gimmick to sell.
I agree, once you get the lossless format, the "sound quality" aspects that most people can benefit from, are basically covered. After that you can chase the "effect aspects" with money, time, and space that may have no value to a lot of people.
One thing that I know you don't believe in or care about is REQ. To me, if someone comes up with a system that is more effective, flexible and easy to use (like turning on/off, making selections by just cycling a button etc.), it would be worthwhile to trade in whatever one has.
Such REQ system should include, but not limited to the following:
0. NO Down sampling, or at least make it optional to down sampling to 48 kHz only if processing power needs to be freed up for enabling certain other optional non essential features.
1. User selection of the upper frequency limit where EQ would have no effects.
2. Ability to store alternative EQ data set for the "main seat" positions, not just position "1".
3. User can select any of the data set in 2. depending on his/her seat position.
4. In addition to 2. and 3. above, system will provide a default position that the system determines to have the best overall effect.
5. Fully editable, within reasons..
6. Provide user selectable limits with hard stop/final limit set by the factory, for boosts, to avoid damages.
7. High resolution displays that show the before/after effects (a must), better still (a tall order), can generate REW like kind of graphs (even if that requires the use of a PC).