Fujirumors is again sure that Fuji is developing a new larger than APS-C sensor camera:
Fuji is working on a bigger sensor camera. The source would like to specify, that the release of this bigger sensor size camera is everything else but imminent (so don’t expect it to come anytime soon). We are just in the early stages of its development. But, always according to this source, Fujifilm is already paving the way for its arrival, since some of the recently announced/released Fujinon XF lenses are already designed to cover the bigger sensor.
Would be nice to have a real Sony FE competitor! But for now even if the rumor is correct it doesn’t sound like this will come within 2015 :(