My opinion is that the fonts are definitely not correctly optimised. I think they require some serious hinting, the anti-aliasing on a lot of the vertical lines is really really bad. Great idea and I applaud the effort, but Typicons need some serious work before I'd consider using them.

As already pointed out, reminds me of Font Awesome: http://fortawesome.github.com/Font-Awesome/ - which did it correctly in my opinion and perhaps Typicons can learn a thing or two from that.