If you're going to take the time to dig through twitter for that you should at least post my responses:
https://twitter.com/#!/bcardarella/status/55023955676905472 https://twitter.com/#!/bcardarella/status/55024200456474626
The point of HTML5 is semantically better elements. div#header is not the preferable HTML5 element. Neither is div#footer.
html5boilerplate.com should be dog fooding. It's not.