Not our error, but Steve Jobs'. The iPad (or some iPads) has a bug whereby they can only see the first <source>> element. To get around this, simply ensure that your .mp4 movie appears before your nourishing royalty-free Ogg Theora or WebM movies, so reverse lines 2 and 3.
Our margin note saying that Opera will implement getUserMedia on the opera object is incorrect. In its Lab builds, it's on the navigator object as specified.
The API has slightly changed; it now uses JSON rather than string for options, eg navigator.getUserMedia({'video': true, 'audio': false}, successcallbackFunction, errorcallbackFunction) .
The spec has been split out from HTML5; it's now part of WebRTC. [January 2012]