No, not at all. But there would be a requirement to design one or two new very wide angle lenses to make up for the difference. At a guess that would be a whole lot less difficult than trying to get a full size sensor to work with existing lenses which were not designed with shiny digital sensors in mind.

Mind you I'm not sure how big that market really is. I have a Voigtlander 21mm lens which I like very much and which I use with my film Leicas (I also have an MP) but personally I don't find I use it nearly as often as longer lenses.

Henry