@dgatwood - i don't think this is a bug. i may be missing something here, but 'autoplay' is a boolean attribute, which i understand to mean that if it is present in the <video> element it's necessarily true, and false only if absent.
html5 specs state:
The values "true" and "false" are not allowed on boolean attributes. To represent a false value, the attribute has to be omitted altogether.
this would mean that <video autoplay/> autoplays, and <video/> does not.
read more here:
http://www.w3.org/html/wg/drafts/htm...ean-attributes