If you got this to the point where you could scan a document and have it spit out latex code for the whole thing, you would have... ... a huge success on your hand. EVERY mathematician I know, most certainly including myself, would use it constantly. I have pages and pages of disorganized handwritten notes.

Since this is a forum for startup founders, put it this way: such a scanner would be of more use to mathematicians than, say, the sum total of Elsevier's output, and their latest financials show annual operating profit in the ten figures.

FOSS would of course be even cooler (IMHO). But, food for thought... :)