Well they do actually.<p>Right now: Firefox is the only platform-neutral web browser. Firefox on Linux and Firefox on Windows are supposed to be the same browser.<p>Using OS codecs changes that, which means a Windows shop can test Windows browsers, but no (reasonable) way to test Linux browsers.<p>So long as there is a platform-neutral browser, browsers have to work similarly.<p>If you remember: Microsoft IE for mac and for windows operate so differently that they must be developed for as separate browsers, and yet banks <i>regularly</i> told people to use IE (despite the fact that IE on the mac didn't work either- and the bank programmers had no way to test it).<p>Content producers earn on eyeballs, and if 10-50% of their users aren't seeing what they want them to see, they'll adapt: browser sniff, flash fallback, or whatever it takes.<p>As a result, video will remain complicated. Maybe Apple and Microsoft can be pressured into supporting OGG, or maybe their users can be prompted to get higher quality video by downloading some codec or plugin. Maybe a technology like ChromeFrame will become popular.