A 54x40,5mm CMOS back with 41.5mp... Double DF's low light abilities, Double DF's IQ, fast enough for sports, dream back for view & tech cameras, I believe it sweeps the cards off the table. If followed be an MS version... game over!
What is missing? hmmm... a C645 resurrection!
I believe if one looks on peoples responses, he should come down to the following conclusions (on that order):
1. What matters most for the majority of people is sensor size over resolution.
2. High quality LV performance is a crucial factor for investing on an MFDB.
3. Ability to use the back with extreme movements on view/tech cameras is required additionally to performance on DSLR bodies.
4. Considerable improvement on higher ISO quality is required.
5. Anything else that differentiates the back from competition and makes an additional purchase obsolete is welcomed (multishot ability, long exposures, video ability, interchangeable mount plates... etc).
6. Price
If a maker comes with such a back, I believe he will crush the market (and will give a new boost to MF). IMO, I can see no other (out of the current) maker able to come with such a back than Sinar... I believe that if Leica's new sensor (for the S007) technology, will pass on to new Sinarbacks (which is very possible since Sinar is a "family" company now) and thus, a back that will combine all the above is very possible indeed.
I don't say this to provoke Brian's plans, I only suggest that another company entering the MF digital market must consider not only current offerings, but future possibilities of offerings in addition.