well, i'm starting down the road to math major.
For graduate-level mathematics, I'd say that LaTeX, and a text editor that does good LaTeX syntax highlighting, would be virtually essential. Aside from being able to typeset professional-quality mathematics, LaTeX is the best way to type mathematical formulas without losing your mind. Consider what this article, which was written in LaTeX, would look like typed up in Word.
Most interesting. I can't see the pdf on this computer (it's a work computer), but I've tried doing math in Word. IT IS HELL. Google Docs is surprisingly compatible with math. Not super great, but it's possible and easy to use.
At the very least, it sounds like LaTeX would get me through my next quarter of precal.