Heading styles (whether in HTML or word processors) have long been a source of annoyance for me, because they constantly have to be redone.

Current models all follow the top-down approach -- assume you know your top sections when you start (H1), then drill down into H2, H3, etc.

But just as often you want to do bottom-up -- start with a short article with a single heading (H1), then add a sibling section (turn both H1's into H2's, add the "real" H1), then put those both under a larger section (H2's become H3's, H1's turn into H2's, new H1), and so on.

Any manual choice of heading levels is just dumb, frankly. <h> is a great solution -- I just want to see something similar for word processors as well!