Although I haven't tried it with formulas, you should also be able to use LaTeX to create SVG content. That's how I create my title pages for my EPUB books, for example (to preserve strict formatting in a device-independent way, while retaining text searching). The basic process is as follows:
- Use LaTeX (in my case, dblatex with XeLaTeX) to produce a PDF.
- Use Inkscape (and/or its command-line tools) to translate the PDF into an SVG file. (In OS X, for example, you can install Inkscape, then type /Applications/Inkscape.app/Contents/Resources/script --without-gui foo.pdf --export-plain-svg=foo.svg in Terminal.)
- Either drop the resulting <svg> tag and its contents into an HTML file or import it with an <img>, <object>, or <embed> tag.