I'm so tempted to point out the bleedin' obvious flaw...Open Source is great for software and firmware but sensor hardware actually needs to be paid for.
Yes indeed: just like the fact that all that wonderful open source Linux software needs to run on proprietary processors, and for the average home user only reduces the total cost of a working computer by 10% to 20% (The open source cost benefit is far greater for heavy duty users like my parallel computing colleagues, who get gouged far more on proprietary software licensing).
A major issue, often glossed over, is the issue the cost of larger than mainstream sensors, and in particular the large R&D costs that must be spread over a relatively small sales volume (compared to say the 10,000/month stated by Nikon for the for the D3, or the 70,000/month of the Nikon D300, and far more for various less expensive DSLRs). The scary bit is that MF sensors would probably have to cost a lot more than they currently do if Kodak and Dalsa had to defray all the related R&D costs over just sales for MF cameras and backs, instead of also selling the same core technology in a far larger number of sensors for medical, engineering, scientific and military customers.
