Peter - Amen on the fat pixels and retained form factor and switchology.
Like your wish list. Have two units - one designed to retro fit to existing R8/9s a la existing DMR and a DMRII + Body Kit for digi-only shooters that is the DMR unit, with serious sealing gaskets (making the 'back' only removable at service center) fixed to an R9 clone gutted of the film hardware. In its stead would be ant required commercially available electronics (most would be in the back anyway), maybe two smaller LiO battery compartments (vs one honking one), dual CF slots, etc.
Still think LV tap for off-back LV and storage backup via a commercial product on a ball/joint cold shoe. Custom cable and work with screen vendor on firmware required in camera -- and on the interface cable. Since Leica's sales would be minisucle to a big electronics house, make tech avialable to others - just be the first(?) to exploit a LV tap.
The idea is to keep the costs down while avoiding ANY margin-killing (and potentially product killing) feature creep during the design process. Keep it simple, keep it basic and don't try re-inventing the @#$% wheel by using off-the-shelf (OTR) tech when at all able. Change as LITTLE on the body as humanly required (keeps machining and mold costs down) and make it durable. FIXATE on IQ at reasonable ISO levels with MF only and maximum usability. Period. My R8 was the first SLR body that I actually WANTED to hold. It just felt so right in-hand.
Don't even think of taking-on the D3s, 1Ds3s and A900s (if it ever gets released) of the the world, not even tagententially. To do so is a bankruptcy or 'crippled-then-acquired' waiting to happen.
Side-step the big lads and exploit a market that their "... more buttons, bigger screen, add video, more sub-menus, "CS3 Lite" in-camera, touch scroll wheel, ISO 50,000, 16 fps, etc ..." arms race could never allow them to. It's a small market, but if you leverage off existing tech, keep the needless costs down and focus on what really matters, is perfectly workable.
Treat it like a portable, weather sealed, fully integrated 24mm x 36mm backup body, sans AA filter, for a MFDB shooter that can shoot R or their existing Hasselblad or Mamiya or ___ MF glass via adapters - but at a 1D3 or D3 price point.
OT: I fixate on the iPod Touch in my earlier musings because it was the first one to pop to find. Used an 8GB one (have God knows how many Apple products we have in house) for first time on weekend and was blown away - and it takes a LOT to impress me.
Amazing screen tech, fast processor, gobs of features, easy to use, no proprietary web gate way BS or idiotic buttons, yet wifi and up to 32GB of flash storage in a light form factor for under $600.
Actually one of the first things that came to mind when playing with it (other than how to persuade wife I needed one) was "... (insert expletive here), this would be a hell of an adjunct to a DSLR or MFDB shooter...". Sad really.