Originally Posted by HawaiianOnline 
I don't know about that. The widest 645 lens I have is the FA 645 - 45mm with a horizontal FOV of 67 degrees. Wouldn't a 1.5 crop give it a 44 degree FOV, which is not much better than that of the 75mm lenses on a full size 645 frame? I guess the gist of my argument is the loss of the wide angle end. If Pentax were to go with such a crop, then I'd expect them to engineer some new DA 645 wide angles with focal lengths smaller than 35mm (their current smallest).
Good point. However, on the other side of the coin, that did not seem to slow down the DSLR manufacturers all that much. Instead, as you suggest, it might simply drive the development of wider angle MF lenses to better deal with the new crop factor.
stewart