It's probably got something to do with the need for ever more specialized connections between lenses and sensors. Look at what Leica is doing with the M8, with micro-lenses, firmware dealing with cyan drift, etc.
It not only costs a lot to integrate a full line of lenses and sensors, but hte requirements are getting ever more critical: the days of "slap the film back on" are long gone, but our expectations haven't. We want an open system, but flawless performance.
This might not be so easy to achieve - and the manuf. are having a heck of a time figuring out whether to close the system, and aim to achieve better integration; or leave it open, and pick up not only additional responsibilities (oh, why can't my Zeiss lens be coded for the M8?), but also figure out how to get paid for providing an open system.
All this, and being chased by the high-end DSLR's from Canon et al as well. Glad I'm not in their business!
None of this stuff is perfect and I guess it will all get better.
The thing I dislike about digital capture is all of the proprietary schemes that the manufacturers keep cooking up.
Our wide angle will only work with our "new" camera and of course only with "our" back.
Our new camera will only work with "our" back and then the thing of open source code that isn't really universal (dng) or open file formats .mos that 3rd party convertors only read a part of the settings makes no sense to me.
Imagine Kodak making a film that only worked in Kodak cameras and in Kodak processors with Kodak chemistry. The outcry would have been huge.
Now imaging buying that Kodak camera and being told the only way the new wide angled lens works if you buy the newest Kodak camera and only with a new Kodak film.
That's the way I see all of this and the manufacturer's can talk about specialized processing, special lens correction, etc. etc., but I think we all know the game is to get you to buy into their system and keep upgrading you in that system for your entire career.
Lecia, Sinar, Leaf and Hasselblad can talk all they want about the benifits of their closed end system, but to me all of this is silly.
My original 1ds shoots as good if not better today than it did when I first bought it. My processor options are about unlimited and just about every lens Canon makes will fit on it and work as well with it as they did with film.
My P-30 works fine on my Contax and if I'm tired of that or want to change to a Mamiya or a V-system Phase will change the mount for a very low cost (or I think maybe free for the first 12 months).
Personally, if Leaf, Sinar or Hasselblad want to move us in thier direction of digital backs then just make a better digital back. One with a great lcd, in camera useable jpegs, higher iso. all open source processing options, solid robust software and most importantly the ability to easily switch from camera to camera.
Spend more time writing grey balances and input settings that more resemble film and less time thinking of some way to force me to upgrade to the next level of back, (camera included) or become locked into just one manufacturer.
Don't get me wrong I find all of this digital capture stuff amazing and the fact that I can shoot thousand of drums scans in a day is beyond what anyone thought 10 years ago.
Still, we I look back at how useable my original 1ds is and how easy it was to develope and build a workflow, I see most of these new annoucements to be a step back, rather than a step forward.
When I use my Contax my P-30 and even my A-22 I really wonder what the HY6 or new hasselblad will really give me that I don't have already, other than more cost and quite frankly more limitations.