I'd be interested in this too - I've always been interested in font design, but not being a professional font person I don't feel like paying for it - especially if it isn't OS X native.
However, there is probably limited usefulness in Photoshop or Illustrator because a good font has a lot more than just shapes. You need to design the characters to fit the physical space of a glyph, and you need to do all the kerning and ligatures and stuff.