I don't write my equations by-hand the same way I do on the computer. For exampl...

I don't write my equations by-hand the same way I do on the computer. For example:

    ( (1 + 2)/(3 + 4) )**2

vs.

       ,                .  2
      /      1 + 2       \
     |    -------------   |
      \       3 + 4      /

The difference may seem subtle, but it's shockingly important. A better example may be

      ,-, b
      \
       \    x + 1  dx
        \
     '--' a

instead of something like

    trapz(a, b, @(x) x+1);

The truly human way of writing down math requires much more flexibility than a typical text editor can really afford. This isn't to say that some sort of pseudo-visual programming is Teh Futar though.

(I do think a LaTeX --> solved expression tool would be awexome though.)