I don't think you can get much in these previews of pre-production models, aside from general touch and feel and ergonomics.
The camera is incomplete, which is made clear by buttons that don't work. And any photos taken with it probably couldn't be fairly judged, as the programming hasn't been completed.
However, I'm with Frank and I'm not sure that I would plunk down my money for the privilege of being one of Fuji's beta testers. And that's the reality of any radically new electronic product or software.
Hey, remember about six or seven years ago when morons were bidding on the rights to buy Canon's full-frame SLR? Not buying the camera, mind you, but just to get in line to buy it. I think the same thing happened with a console video game at Christmas a couple of years back -- before the big crash slapped people back to reality. But I guess if you have the money, go for it.