Just for the information, the project page[1] mentions that this is under "Attribution - No Derivatives"[2]
Typefaces can not be copyrighted. (The actual font file can be, but not the shape of the letters.)
This is a slightly edge case since the letters have considerably more art to them than the typical letter, but they are still letters, and he has no legal ability to restrict what people do with how they look.
If calligraphy can not be copyrighted (and it can not), then this can't be either. So his license does not have any force of law behind it.
http://en.wikipedia.org/wiki/Intellectual_property_protectio...
His page mentions that he is from Hungary, and this restriction may have the force of law there, I don't know.
I suspect that most people who would want to create a derivative work would want to reuse the existing files. Manually re-creating a font is quite a bit of work. Finding just the right control points to get the curves perfect is tough. And no, you can't just dump the control points out of the original file; that would be creating a derivative work.
Edit to add: And actually, I believe that the copyright notice on that page is for that sample, displaying how the font is constructed. This is something that is copyrightable. The actual font file doesn't seem to have been released.
The small modification you make to the shape are not considered enough to give you copyright.
> could someone take a bitmap screenshot of Helvetica, product a font from it, and distribute that font?
Yes, and not only can they, people in fact do it. That's basically what Arial is, and there are open source versions as well.