the pen will move according to the font?
that's crazyness.. that futuristic, idon't even think thats possible. typographic studies showed that each handwriting is different and you can even conclude certain properties out of handwriting..
now a certain pen has to be familiar with all the ways people write stuff down, which are to many..the argument against that could be that you built a censor in the ink ball at the end (the point), which wouldn't be influed by the movements you make with the pen, just the letters itself..but than you still would have the problem that some people write more slant than other for example.
i don't think this idea would work. it would cost to much research engineering for the result that it gives.
..maybe you can copy it later off a device which is already been made in the future..