On a related issue, I would really like the HTML5 standard to require a minimum <audio> and <video> codec, even if its something really old and dumb. There are lots of bit-rate applications (sound in web applications, animations) where something old and dumb is all that's needed, and it would be nice to have some requirement in this area, even if we can't agree on one for the higher-bitrate applications?
For example, an uncompressed or low compression audio format (e.g. some variant of .WAV) is great for adding custom alert noises to a web app, so support for such a format should be mandatory. Similarly, if some old/dumb video format was mandatory, it might be unusable for real video, but still might work perfectly well for animations, presentations, etc.