They do state that they intend to support Firefox for the final release.

And I think in general, letting average folk see something half finished and probably broken will totally prejudice their opinions of the final product. Irrational, but true.

So that's it we amalgamate HTML5 video and H.264 already ?

What does the codec have to do with the player?

There is no "'HTML5' VIDEO".

AAPL and GOOG can use VIDEO tag for H.264-encoded video.

Mozilla and Opera can use VIDEO tag for Ogg Theora encoded video.

There are two distinct implementations: VIDEO/H.264 and VIDEO/Theora. Neither supports the other.

You got suckered by the "'HTML5' VIDEO" talk. Not your fault; even its proponents didn't address such video basics until it became too late.

OK, but I don't see why the player needs to be tailored to the codec. Why wouldn't this player work for Theora as well?

Good point: Could you use the Sublime HTML/JS set for other codecs? Probably could -- the codec would make less of a difference to transport control functionality than the browser's varying support for JavaScript and VIDEO APIs would be.

Yes, all that's necessary is for the content author to provide a Theora encoded version of the video.