5 years from now, cameras will not have mirrors. Even the high-end.
Both APS and FX will go through a transition similar to the 4/3 --> m4/3 transition, that will include an adapter and some new lenses.
We were hoping Nikon would start the transition now, rather than introduce this. The target audience would benefit just as much from a non-interchangeable lens camera with a sensor of the same size.