Amateur Photographer interviewed Mr. Hiroshi Kawahara from Fuji. And he confirmed that “Fujifilm technicians are seriously investigating the possible launch of a full-frame compact system camera (CSC) and are focusing on the sensor and processor that would be required.” Mr Kawahara also confirmed that “the covering circle of Fuji’s current X-series lenses is large enough to accommodate full frame.” The problem is that current wide angle lenses would not cover the full FF area.
http://www.mirrorlessrumors.com/fuji-may-go-full-frame-mirrorless/
http://www.mirrorlessrumors.com/fuji-may-go-full-frame-mirrorless/