Regarding what humans are calling "medium format" digitals.
The current crop of digital cameras (at 6 to 10MP resolutions) has already almost killed the film medium format segment of the photographic market.
And using current pixel sizes, 22 to 25 MP resolutions are soon very likely (in 24 X 36mm sized sensors).
Discussion of digital "medium format" seems to me to be humans overlaying yesterdays practical need, onto today's technology. In other words, yesterday’s world had a practical need for medium format cameras. I am not sure this will ever be true again. Possibly it might be true, but just because medium format thrived in the past, does not necessary mean that it will in the future.
Of course there will be some limited production medium format digitals, but expecting to see medium format digitals sales like the Mamiya 645, or even the Hasselblad 6 X 6 is unlikely.
Wedding photographers were the huge market for these cameras, and currently most wedding photographers are extremely happy with their 6 to 10 MP cameras built on 35mm like bodies. With room for these same 35mm like digital bodies to grow to about 25MP, I suspect the medium format digital will be at most a niche market, more likely to replace 4 X 5, and larger cameras, for the no compromise, ultimate image fidelity, crowd.
Wonder if anyone is at work on miniature view cameras that accommodates all the tilts and shifts and happily mates to a digital back with a image sensor about 2.25 X 2.75 inches in size. Short mount lenses in the 40mm focal length range will also be needed. The longer focal lengths are already all over ebay for a song, better snatch them up now in advance of the market swell.
But, about 5 or 10 years will tell.
Enjoy! Lon