I know many here are very versed in MF but a just as many or more are not and see that many are missing the point.
Simple if you can't see the point in MF then your not aware or it, simples. let it lie it's not for you don't pipe up with unsubstantsiated thoughts.
Basically canon rocks for day to day professional shoots and up to fairly hi-end but the MF optics and especially phase one backs offer another league up in terms of image quality and MP, but in lowish light is you thing then probably best with canon FF- though the new 50mp CMOS sony phase one and hassy will be awesome for a more rounded use. The game has changed right now. And Canon will have to do a shedload to win in this market now.
If we got a MF 5D III similar with autofocus to boot and something like the 50MP sony sensor them many pros may change system.
If you use hi-end strobes / studio work on controlled shoots all the time on decent budget shoots say $2-5000 per day then MF is perfectly viable either to buy or hire. But the the crus is many MF users are seriously bought into hassy or phase glass already so canon would be a bit late in the day. Some retailers will offer decent money for swapping systems espc from hassy to phase one. So this may well continue if Canon got into the game.
Every one I know who has a phase or hassy also has a 5D III pus much L glass , most prefer using the canon but when in an controlled environment the hassy or phase shines . Its horses for courses completely.
16bit smoothness plus better optics will win every time especially when making images for billboards and pushing files in retouching , if its for magazine adverts or 6 sheet then canon is quite capable . And if you bitch about the difference its not for you. yes you can make a canon in controlled environments very nearly as good as as 30MP MF file and only a few would notice the difference, but art directors and clients often do .. don't underestimate them.
I did think Canon had a good chance of entering the MF market until last month when Phase and hassy announced the noes 50MP CMOS sony sensors into their line up.. I think Canon will be gutted about this as anything they have been developing is too late at this time.
Unless they are going to come out with a super sized DSLR or camera / back system in the next year that out shines phase one espc , it would have to be as responsive as 5D III with all the same DR and noiseless of the sony but there's also the leaf shutter sync (i.e. up to 1/1600s which adds so much versatility to shooting outside with flash) to add into the mix that I don't think they'll do without a huge investment in lenses .
Phase one , leaf, mamiya etc are so well thought of by customers and the owners that I doubt an interjection buyout/ merger from canon would be feesable . Its like thinking audi, lamborgini although make super cars could try to merge in with ferrari its not going to happen ever.
if canon were to enter MF it would probably be very similar to leica's or pentax's MF effort which is good but not hassy or phase territory.
They would have to come out with a completely new system better than phase ones, at a simlar price point which would take many years to out sell them.
I think best we can hope for is the 40+ MP FF sensor camera with equal to sony sensor DR and noise. All dev so far points to lens being upgraded first which is logical and sigma following suit and possibly beating canon in quality to date.
As much as I'd love Canon to come out with a 1D / 5D AF based camera but 40+ MP sensor with great DR and no noise in shadows & banding etc many of the lenses would not handle it properly but seems to me sigma are ahead of the game , the 35 1.4 is outstanding as good as the 85 1.2 II in my experience, the new 50 art will be stunning i'm sure and canon had better wake up to this.
One thing for sure in terms of photographers is still image quality. is this being developed in secret or simply put to the side to exploit video to make money for the corporation. 1Dx pro press base will always be high but seems that its been many years since the 1D3s that ruled the pro high end FF user base and has been forgotten about for many years which many are getting restless of that I speak with.
Can't wait to see canons next move to regain this market this year.. if it's not till next year then it will prob be too late.....but i they make as much or more from the 4K video market then Canon will be doing well in business terms even if they loose a previous core customer base. And business change and diversify all the time, but it would be big shame to current uses.