No one will remove H.264 - it's a great codec with wide support. It's more likely that we'll be in a world with two good video codecs, not just one. VP8 will hopefully become the HTML5 video standard, and H.264 will remain in Flash (which will still be useful for a long time), most browsers, many mobile devices, and on the desktop.
Incidentally, this has been the state of audio for a long time - mp3 and aac are both good codecs, and both are really widely supported. (Vorbis is reasonably good too, though not as widely supported. Maybe that will change with HTML5.)
Incidentally, this has been the state of audio for a long time - mp3 and aac are both good codecs, and both are really widely supported. (Vorbis is reasonably good too, though not as widely supported. Maybe that will change with HTML5.)