Earlier quoted context omitted.
This is comparing apples with oranges. HTML5 games are meant to compete with current flash games, not with native (and far more expensive to create) 3D games like the one in the video. Most of the succesful mobile games are created using a 2d engine. In the future, this could be done using HTML5 and its nice to see that some pioneers in the field already release engines to play around with it.
HTML5 is very much competing with native as well. HTML5 vs. Flash is just games on Kongregate etc, if that's all HTML5 does, if it even does, then its failed as a casual gaming platform.
P.S: Again the future of IE comes into play. Will they support NativeClient or stick to ActiveX stuff.