I open this bug to track MathML issues that prevent the Webkit MathML support to be enabled by default in MathJax or future MathML bugs that could be reported by the MathJax team. This bug may also help to track possible improvements to the Webkit MathML engine related to MathJax implementation (like supporting MathJax fonts). More and more people are using MathML throughout this library (the Wikipedia folks plan to use it) so that should guide Webkit developers towards the most important MathML bugs/features.
This page gives an overview of some issues with the MathML code generated by MathJax from LaTeX commands:
I've created a couple of bugs regarding features that are not implemented in Webkit yet.