There is a fly in the ointment of HTML5 <video> adoption. There is still no agreement on a single encoding standard for video. Among the most popular browsers, Safari and Chrome currently support H.264 for <video> and Internet Explorer 9 will support H.264. Chrome also supports Ogg Vorbis and Firefox only supports Ogg Vorbis. What is a website to do? Most will ignore Ogg Vorbis and put up H.264 with a fallback to Flash to play on older browsers or Firefox using the same H.264 they encoded for HTML5 <video>.

Gruber has a well reasoned argument of why it would make sense for Firefox to adopt H.264 for HTML5 <video> here. His argument is based on the history of GIF and PNG and an interesting conjecture about the future of Ogg Vorbis.

AuthorMichael Slade