- keep the same form factor but improve the sealing as no dust must be found on the senzor ever again;
- keep the sharpness of the lens and maybe improve the close-up distance;
- improve the manual focus and add some aids, making the camera a better choice for product and close-up photography;
- provide true film simulations for all Kodak films, otherwise you won't stand a chance against Fuji invasion of the niche (because X70 already gains terrain).
Or ignore my suggestions as these are coming frum a guy who still shoots with a Panasonic P&S camera and a Minolta SR-T 101 film camera.
Or make a new GR line of rangefinders cameras with interchangeable lenses to punish Fuji for invading your territory.