If the X-E3 gets a tilt screen, hopefully it will be fully-articulating, like on the Panasonic GH4, Canon 60D. Failing that, the standard tilty-flippy screen would be preferable to a fixed screen like the X-E1, X-E2 have.
Either way, I would really appreciate a touchscreen, even thought the button-oriented Fuji menu is nice once you get used to it.
Interested in an improved sensor, higher megapixel count. Minimum 24Mpxl, please.
Would really be interested in improvements in: shutter speed, fps, and buffer/memory and Autofocus performance (esp. tracking).
Video improvements would be very welcome. 4K, please? It would be nice if Video functionality was more than an afterthought. It's too bad that my smartphone seems easier to shoot video with.
Additionally, IBIS would be fantastic as it would give stabilization to any Manual lens. There are a few non-Fujinon Macro lenses that I'm keen on that would benefit.