Short and spot on, the way I like it.
It was always clear for me that we are only at the start. With more MP, the medium, the pixels, will become less important. Realtime processing with incredible spatial and temporal resolution, emulating of brain functions, and whatnot. Our eye is a very simple lens, but brain makes up for it. Thats the direction I expect the whole thing to head in the long term: Incredible computing power and sophisticated algorithms, compensating for everything else. Eventually even the high-end optics of today will be replaced. Maybe in 50 years?
Interesting speculation, but I think it's a bit misleading. The relevant issue remains the final destination of the image being captured.
If the destination is a physical print, then there are some fairly solid and easily calculated horizons, beyond which further pixels/resolution/dynamic range really don't add any useful information. The resolution/perception limits of the viewer's eye imposes finite limitations. Current generation inkjet printers already exploit this; 300-360 dpi dithered output sneaks in below the capacity of our eyes to detect the illusion, without optical assistance. Yes, a gi-normous file may permit you make a print that is (say) 10 by 15 meters in size; but why would you want to? Such a print is far too big to be constructively engaged in almost any venue, to say nothing of storage and transportation problems. The exquisitely crafted fine print that can be held in the hand or appreciated on the wall is a beautiful art form that remains traditional photography's benchmark. I would argue that the current generation of high-end digital backs are already rapidly approaching the point of diminishing returns.
On the other hand, if the goal is a notional three-dimensional holographic projection using teraflops of computer power and advanced projection to create a completely credible illusion of physically being in the subject presence...now you're talking! There's plenty of head room for future leaps in dynamic range, resolution, real-time tonal adaptation, continuous video holographic capture...
But then you're not really talking about photography anymore. It's some other kind of art, but not photography as we know and love it.