1. I think you would be better using `keyup`, since that fires after the browser has already created any new elements
2. I think you can actually short-circuit this. If the key wasn't the kind of key that could have created a new block element, you don't actually care about it. Check out the `keyup` handler in `wymeditor/editor/webkit.js` and that's an example list. Sounds like we probably want to make yet another constant so that we can do that detection specific to the browser.
3. You're also going to need to handle the click event on the containers UI element, since someone could use that to change eg. a paragraph to a header, or visa-versa.