NOTE: I am locking this question to make sure that people who have problems with the MathJax TeX rendering post their issue as a new question, rather than an answer here.
(This question was put up to deal with the immediate feedback when MathJax was first implemented.)
Per the most recent edit here, meta.math.SE and math.SE now have MathJax instead of the previous Google-Charts-based rendering. Feedback thus far?