I was interested to read Trey Ratcliff's essay about the future of cameras.
While I certainly agree with him in principle, I'm not so sure about timing. That is, it's certainly coming, for many good and valid reasons, but he seems to be saying that it's right around the corner, and I think he's a bit early, there.
I'm fairly sure that the next generation (iteration, if you prefer) of top-of-the-line cameras will be SLRs, and I wouldn't be terribly surprised if the generation after that is, as well. But I wouldn't be at all surprised if the generation after that is a mirrorless camera. I would expect it to be full frame (so, bigger lenses and bodies than what we're currently seeing), with a much fuller selection of lenses than any currently available mirrorless system.
I'm kind of looking forward to it, actually (even though I have a new SLR on order). One good thing is that lenses should be quite a bit cheaper. One nice bit about never having a person looking directly through the lens, is that even the viewfinder image (whether delivered to the back of the camera or to an eye-hole through the back of the camera) can be digitally corrected for various lens imperfections. That should lead to fewer tradeoffs needing to be made during engineering, and, therefore, cheaper lenses. We'll see, but I think that's one factor.