Well, it only triggers if you already have a space after the tag name and before the >, so otherwise you'd be trying to put in two spaces: "<div >". How often do you do that?

Spoke too soon. If you have, say, "<div id="foo"[CARET]>" and press space, then it pops up too. That's kind of annoying. Is there something that can be done about that? (Though I admittedly haven't looked at the code and know nothing about the HTML language definition, seems like it might be hard.)