I've looked at Theora and I would not like to have to implement it. It looks a bit of a mess - many design decisions were not justified, simply trying to avoid using something like H.264 to avoid patent issues. But at the end of the day there are only so many ways to encode video efficiently that we know of, inevitably they chose similar but ever-so-slightly different schemes. With their hands tied in this way it is difficult to make something better.

WebM, http://www.webmproject.org/about/, specifies VP8 video and Vorbis audio so for all remarks concerning video quality WebM/VP8 are interchangeable. Iff VP8 quality is "as good as H.264" I would like to see scientific proof.

Google aren't avoiding H.264 fees because, as I said, if they continue to support H.264 video in a Flash container they are just as liable. It's politicking because as Fab said, it makes no difference. I prefer to wait for HTML5 and see if W3C set baseline format support for the video tag; they never specified what formats were supported for the img tag so it could be that they do the same thing again.

My point was that Matroska files are not supported by professional video editing tools.