I'm not sure. I think it will be more of a hit, actually. I think a system camera has inherently broader appeal than a fixed lens camera with a single focal length. Also, the price is more than I can afford, but not unreasonable if you compare it with a high end aps dslr like a canon 7D. Wasn't that model about the same price when it was launched?
I see your point, but I'm not sold. The X100 was the first of its type and was priced way lower... fixed lens is a minus to some and a plus to others. $1200 got you a body and a lens. Now, it'll be $2300 for the same. Still reasonable to me, but likely many will still opt for the DSLR option since it is the mainstream camera type in use and is more versatile for seemingly less money. Many mainstream camera buyers think zooms are cool.
As for legacy lenses, no camera has done it 100% right yet and suspect the X-Pro1 won't either.