It might be kind of early for this, but having had an OB-X8 for about 9 months, I have a number of things I wish were different, that I think would make it perfect. There could be more, and feel free to add suggestions, but this is what I have so far. It's possible that some of these changes could be made to the OB-X8 in firmware, but not all, so I am personally hoping for an OB-X8a that's like this:
1. Blue stripes and red power button on the front panel, like the Xa/8.
2. A three-way button on the front panel (Master section) to choose between the three Oberheim models. All of the Page 2 options that relate to the OB-X, OB-Xa or OB-8 change when you choose that model.
3. A button or knob in the Filter section to choose between all available filter types, instead of having to go to Page 2.
4. Stereo Width, Pan Mode, and Stereo/Mono Global (renamed "Output") moved to the front panel with buttons or knobs in the Master section.
5. Tempo sync functions like the OB-6/Prophet-6/Trigon-6, for the arpeggiator and LFOs. The ability to choose an exact tempo for the internal clock (and see it on the screen), the ability to choose note subdivisions (8th, dotted 8th, 16th, etc), and the ability to sync the arpeggiator and LFOs to that tempo. Whether this should be all on the panel or some on Page 2 is something I'm not 100% sure about.
6. Knobs for OSC 1/2 Volume and separate Pulse Width in the Oscillators section.
7. Change the Noise and KBD buttons to knobs with a value of 0-127. Combines On/Off and Amount in one control. Add similar knobs to the Control section for Velocity and Aftertouch.
8. When you turn the Frequency knob for an oscillator, show the pitch on the screen.
9. Page 2 panel mode legends printed under the controls for the remaining Page 2 functions, like on the OB-8.
That's what I have for now. With those changes, I think I would be set for life with an OB-X8a. The ability to add voices is another possibility, up to 12 or 16, but I know that would mean a significant price increase, so it's a separate issue.
A lot of these changes are taking things from Page 2 and moving them to the front panel. That would allow Page 2 to be shortened, and menu-diving reduced, with the remaining Page 2 functions moved to the front of the menu. I think they leaned a little too far into making an exact reissue with the X8, and adding those controls to the panel would be a significant usability/quality-of-life improvement.