Your move Apple: Google announced that they are changing Chrome's support of HTML5 video to be, in Google's view, more friendly towards open development. The H.264 codec is being removed in favor of the Theora and VP8 video codecs as well as any higher quality, open codecs. The resources that were used on H.264 will instead be used in supporting these open technologies.
The changes won't be immediate, as Google wanted to give developers and webmasters a heads up before they remove H.264 support from their browser.
We don't yet know if this means that you'll be able to install H.264 codec support via a Chrome plugin.
Steve Jobs often touted HTML, and especially H.264 as being the future of video on the web. Apple decided to forgo Adobe Flash support in favour of H.264 for its mobile devices, a move that many to this day still debate.
With Google dropping support for H.264, it's hard to say how many websites will keep the codec just to appease iPhone and iPad users.