The question of TeX markup for equations & obscure symbols has cropped
up a few times -- consider it bumped again :)
It's a complex issue with all sorts of technical considerations, which
could clog up this list.
So rather than do that, I've compiled all past discussion I could find
on it on Meta:
http://meta.wikipedia.org/wiki/Math_Markup
It needs a good clean-up by someone aware of the technical issues (ie
not me, I've never even used TeX)