It seems to me that the last big frontiers for mirrorless cameras and small-ish video cameras are internal NDs, IBIS, and quality audio.
It would make a lot of sense for both Sony and Fuji, who have dedicated "video" cameras (A7sII + X-H1) to lean all in. Canon could also do this by making their XC-10/15 have interchangeable lenses and an APS-C sensor.
My dream:
- A Fuji X-H2 that is slightly larger (10-20%) to allow for internal ND (even a drop-in filter like Canon's EOS R adapter) + the XT3's upgrades (codec and AF) with A high-quality XLR breakout like the XC-15 (both Sony and Panasonic's aren't great for professional use). Or even the Pocket 4K's solution of a mini-XLR + 3.5mm and two-channel audio.
That would be it. I'd go all-in with Fuji if that happened - they have the best APS-C lens lineup, beautiful video quality, and my favorite color science.
---
Really amazed someone hasn't put internal NDs in a small, large sensor body yet. I don't really hold out hope for Canon or Sony to do it because they are trying to protect their cinema lines, but Fuji or BlackMagic could easily (I was actually surprised the Pocket 4K didn't have it after I saw how far their mount stuck out from the sensor - looked like it was going to).
If Fuji did the above, anything below $5k would be fair game, IMO.