[whye]

This is a very neat idea, but the lack of support for latex, or any other way to create mathematical expressions is a bit of a letdown.

[mr_dbr]

http://stackoverflow.com/questions/516406/latex-equivalent-t... lists a bunch of possible options that would be rather trivial to integrate (either a modified version of Markdown, or the editor)

[brg]

MathML is coming in webkit. It shouldn't be long before most browsers have support for that spec.