> I'd offer that adding more encumbered formats is utterly poisonous to
> everything that made the web so successful...
Well, this is like saying HTML should have never evolved from version 1 or that the javascript and CSS extensions are poisoning the web. AFAIK not all browsers are passing the Acid3 test and still people don't consider that their web experience is broken because of that. Not all browsers are going to add support for all Matroska support all at once, nor will they with Ogg. That doesn't mean it's not the way to go.