Nobody follows standards the W3C publish just because the W3C publish them. Indeed, if they have a good reason (or sometimes not so good reason) not to, they wo

Nobody follows standards the W3C publish just because the W3C publish them. Indeed, if they have a good reason (or sometimes not so good reason) not to, they won't. Publishing a standard that says "the user agent MUST support Ogg/Theora/Vorbis" doesn't change anything until you motivate the company that implementing that standard is more important than anything else. And as long as IE, Safari, and Chrome all supported H.264 (etc.) anyway, most web developers would just use H.264 thus giving MS, Apple, and Google no (external) motivation in terms of site-compatibility to support Ogg/Theora/Vorbis, and if the market (i.e., browser users) don't care about it — they won't add support.