There's so much potential around the TabletPC and Math.  Folks were buzzing after the keynote where ink was converted into physics animations and equations.  I ever heard people ask “Is it real“ and others insist that clearly it was faked.  Seems to me that while handwriting recognition is a little iffy these days, recognizing numbers and symbols that tend to be a) more varied in shape and therefore easier to recognize and b) used in a more finite domain like Math (as opposed to 100s of languages) would be easier.  The possibilities are endless.  Here's a great app called xThink Calculator (link in French).  Here's something that Loren did for his niece for practice long division.