Web browsers and fonts don't mix well - mathml and latex do not cover the need like (pdf would, but html is not pdf, and browsers aren't adobe viewer), unicode is, well complicated and "on hold". some kinds of fonts can contain virus. and fonts are copyrighted. font servers can be corrupt. and that doesn't cover internationalization yet. it was all perfectly working until web browsers came to into existence imho ! :)
I think it's very unlikely web browsers will do a good job in the thinkable future of rendering special fonts: they (the web browser makers) have no motivation to get it done.
The browser would have to allow (Mathematica) to cut in and render the cells (they can, but it's allot of development overhead on all patforms to do it). MM front end can get browse notebooks on the internet like a browser but there is no server that serves the forum to browse in that form. (and i'm unsure people would prefer it)
Hope that helps. I hope I'm wrong!