Sometimes, when the ol' fever comes back and nobody's there to remind me that we have come to accept HTML/CSS, I dream of a world wide web built on TeX and TeX alone. It's a place of wonder, and happiness, and river-less paragraphs. Then I wake up, sweating, screaming, to a world without proper hyphenation. XeTeX is my XaNaX. Makes the web-pain go away.
[MathJax, on the other hand, looks glorious. Many thanks to the people in charge of the project!]