Optimistically, I can see 44x33mm as simply a good place to start with CMOS sensors in formats larger than 35mm, because compared to even larger formats, this has lower development and manufacturing costs, more potential customers given Pentax's choice of 44x33mm format for its 645D, all allowing lower initial retail prices. Let us see how well it sells, and if Sony/Phase One/Hasselblad respond with further models closer to full 645 format.