It's an interesting idea, but it wreaks havoc with form element behaviors between FF and RoW (rest of world). It also forces explicit font-size declaration for headings, which in some cases could be just more work for nothing. This seems particularly true of checkboxes and radio buttons. If you're implementing custom styles it's a time saver, but if you want browser defaults you just removed them!

Much like Meyer's bloated "reset reloaded" Which wastes time screwing with a bunch of things that don't need to be reset or that you'd explicitly state anyways, by the time you corner case all the places it's likely to just do damage, you risk giving resets a bad name.

When they are a good idea, no question. I just don't think this approach takes enough of what can go wrong into account. I think a lot of testing across a lot of platforms would be needed, and by the time you fix all the little corner case issues you might end up as bad if not worse than Meyer's.

Oh and since you wouldn't want white-space screwing with things like PRE or CODE, rather than targeting just the one element for a fix, I'd move it into your first declaration.