Take my money! I love my Mamiya 7II but I really haven't touched it since I started working with tech cameras. I would wonder if you'd be able to have the cooling and board layout space in something that small, without having the case balloon to be as thick as an old Sony Mavica though. The back technology we have these days just doesn't seem to be anywhere near able to fit into something that slim, or else you might have seen the S system be that narrow, for instance.
Because for me, MFDB brands are a bit on the "non investment " and "I take no risks" side. With the CMOS ships, cooling is less a problem. Phase just released a new "industrial" camera with back incorporated. It is two time slimmer than the previous camera and ... it is CCD. The size difference is huge:
Before
After
The 7ii is bigger or equal, volumetrically speaking
The Sony RX1, very tiny tiny camera, is full frame. Sony craft MF sensors ... logic say that it is possible that one day, sooner or later, sony will release a RZ1, the MF RX1 without any problem (battery maybe).
Mirrorless MF market was too narrow when film was around... It was a small percentage of what used to be a big market for MF SLRs... Now MF market is shrinking year by the year, day by the day... The maker that will "dare" to "invest" on MF mirrorless is for sure a dead duck... No point for it to exist at all... All it will ever do with respect to FF DSLR mirrorless is to (perhaps) increase quality a bit... Who cares? ...Improving quality (a bit) has nothing to do with improving photography...
You very wrong, by a large margin, but I take time to semi answer your biased affirmation. MF market is not very shrinking, it is transforming (and already transformed). On an another hand, photography generate less money than before so investment is slower for photographers. So the MF cameras are more and more RENTED, but they are bought by shops. Once the ROI reached, those shops buy a new unit and sell the used MF. This is a pretty stable market and I think some shop's owner can confirm that on this very forum.
Range finder 120 cameras are legion and was far less expensive (and heavy). 645,680 rf cameras have been sold like hot cakes for decades, more than MF SLR and the second hand market is awesome on it. It is still popular because of a simple esoteric fact: they are cheaper and lighter.
I have high hopes that some manufacturer will come a a mirrorless DMF camera before this decade is over.
Eduardo
Like a lot of people
REFLEX MFs will still exist because of AF and more lenses options, MFDB will still exist because of technical cameras but, what is a FACT today, is that ppl want portable/discrete/tiny gear. Your high hope will transform into reality any-time soon and for that you can say thanks to Sony: Sony shake the market actually. You might say thanks to pentax too, because they shrink the MF price by a huge margin. They want people to stop "renting" MF but "owning" them. Then ppl will invest into their lenses (and you might notice that the new 645 lenses are absolutely not cheap).
So the whole interest in mirror-less MF and even fixed lenses MF is just huge. The threshold is the price and pentax/sony will just make it real (or push others to make it real). For example, if Pentax come with a fixed lens mirror-less MF, it will be cheaper than the 645Z. A LOAD of photographer will buy a unit. This is a mathematical fact proved by today market. Every ppl able to invest in a high end 35mm DSLR and lenses will have the possibility to buy MF (crop) at a cheaper price. A lot of units will sell, a real golden goat.