Yuck, yuck, yuck. You don't want anything of the sort. The correct
solution to the problem is to design an SGML layout language (been done,
aka a style guide) that describes externally to HTML how things should
look. This is a solved problem waiting for an implementation.
This lets authors do presentation and lets users override them (because
it's ugly, or you just feel like playing around, or your work
environment imposes other presentation requirements).
If you want Microsoft Word then distribute your documents in Word format
Consider this case, you are trying to import a document written at site
B for use at your site, however your site has different style guidelines.
With MS Word you might spend 100's of hours reformatting the document.
With HTML + style-guide you just tweak the style guide and boom, you are
done. This is why HTML sticks more with SGML concepts than going pure
presentational. The persentational elements of HTML are for converting
*EXISTING* documents to HTML (e.g., man pages) where you have no
semantic information (just bold/italic).