Adding support for math notation
I believe the MathJax should also work in Stack Overflow, not only in stats, math... SE sites. It is suitable in many questions and answers. It would make such posts much more readable.
Speaking as someone who is both a mathematician and a software developer, I agree that this would be beneficial. However, Jeff Atwood disagrees that the benefit is worth the heavy burden this markup places upon the system. While I do think it would be nice, I'm not in a position to know what the burden would be relative to the benefit.