YouTube using H264 initially may just have been because they already have their videos H264-encoded, because that's what they use for the high-res content in their Flash player. They may also be selecting it because of Chrome's support, but I think it's too early to assume for sure that they don't have plans to support Ogg at some point.<p>Supporting H264 &#60;video&#62; was just a matter of writing some front-end player code (which they already had from their HTML5 demo) and feeding it the same video file they gave the Flash player. Supporting Ogg, on the other hand, would require massive transcoding.