I was watching the Google I/O keynote and was floored by their announcement to release the VP8 codec as royalty-free open-source software. That's a huge development especially from a huge player like Google. They've garnered support from Mozilla & Opera and they're even discussing converting the whole YouTube archive to the new codec so this is a VERY big deal. 

I just found out the <a href="http://windowsteamblog.com/windows/b/bloggingwindows/archive/2010/05/19/another-follow-up-on-html5-video-in-ie9.aspx">Internet Explorer 9 will also support the VP8 codec on machines that have the codec installed</a>. This is equally exciting as it expands IE9's HTML video support to be consistent with that of other major browser vendors supporting playback of H.264 video as well as VP8 when the VP8 codec has been installed on Windows.

You can read more about the details <a href="http://windowsteamblog.com/windows/b/bloggingwindows/archive/2010/05/19/another-follow-up-on-html5-video-in-ie9.aspx">in the official announcement</a>.