Google is forging ahead with their quest to promote the WebM open video codec. To those ends, Google has announced that all new videos that are uploaded to YouTube will be encoded in WebM in addition to the other supported formats. Google is also working hard to get the entire 6-year backlog of YouTube videos converted to their preferred format.
WebM is a based on the VP8 video standard and Vorbis audio. If you ask Google, they claim the standard is completely unencumbered by patents, unlike the current codec king H.264. Others are not so sure, and patent pools are already being assembled to challenge WebM. But that isn't stopping Google.
In addition to the new videos, El Goog has already transcoded videos that make up 99% of the views on YouTube, which amounts to about 30% of the total number. In the interests of compatibility, Google reminds us that H.264 support is not going away (even though it was yanked from Chrome). Videos will continue to be encoded in multiple formats, and development continues on Google's HTML5 video player.