I've been operating a forum site for my topology class. I'm planning to commercialize it. I just need a domain and a few additional features. I'm planning to update and improve the latexrender module to work properly with 4.7. It provides a filter to convert inline latex math text into images. This will of course be extremely useful for a math forum.
Update!
Daniel Gutekunst has picked up a google summer of code project to develop thorough LaTeX integration for Drupal. He calls his module Drutex. Cute :)