Gerald, it is simply part of the compromise. Phase/Leaf are a back system. And as that type of system, they work well. My point was more directed at the camera as a unit and the separate back limits what can be done. I think Hasselblad, Leica, and Pentax are looking at an integrated system. I am wondering how that will impact the Phase/Mamiya line. There are Phase/Mamiya shooters that don't mount their back on anything else. Will the technology benefits of CMOS and an integrated system affect Phase/Leaf? Certainly there is a class of customer that is very used to sophisticated technology in their cameras. Could the move of MFD to CMOS be a large driver in market share for some of these companies? I am just speculating.
Predicting is hard to do, especially about the future.
There's no question that the Phase/Mamiya bodies are extremely basic when compared to almost anything else out there. Coming from a Canon 1D4, I found the auto-focus of the POAF to be so limiting, that the lens collection I've built up for it is almost entirely MF (that of course had an advantage that it kept the price of the collection down significantly).
Personally, I don't really see the live-view benefits that CMOS would bring to be an advantage at all. People talk a lot of the time about wanting decent live-view to be able to confirm focus before shooting, but the reason they want to do that - in my mind - is that they don't trust the focussing of the camera in the first place.
Don't treat the symptom. Cure the disease.
Get something approaching the focussing of the 1D4 in a MF body, and who needs live-view for focus confirmation? I really don't think many professional sports/wildlife shooters using the 1D4 or 1Dx use live-view for focus confirmation. They don't need to. They know that - used properly - the camera will pretty much nail it every shot.
What I'd like to know is what is stopping MF manufacturers from bringing out a body that auto-focuses well enough* that live-view becomes a non-issue?
/edit
* for clarification, I should probably have said "a body that has great AF functionality such that..."