In reply to Opinions about a font combo making website. :
Of course this sort of thing would only work very well if we had a robust feature-based font classification system, which we don't. Even then somebody would have to manually classify each font - I wouldn't expect it to do that on its own.
But even without a good font classification system such an algorithm might still serve as a fallible guide that gives ideas, many of which a user would reject.
hhp