We have known for a while that VP9 was coming, the codec successor to the increasingly-used VP8 codec. In May we learned that VP9 was nearly ready and now as of today it's enabled by default within the latest Chrome web-browser.
Per this Google code issue, "media: Remove VP9 flag, and enable VP9 support by default."
The VP9 video compression standard offers many improvements over VP8 to shine as Google's next-generation open video standard. Today also marks the day that the VP9 Bitstream is considered frozen.