I think a lot applause has to be directed at Adobe for making SWF and FLV fully published and open to anyone to build upon. This is what I call a fully spec’ed open standard. Not the half-spec’ed ooxml.
I guess leadership in this space clearly belongs to Adobe. Now to get gnash fully functional – or better yet, Adobe open sourcing their flash players and putting it out on a GPLv2 or even a GPLv3 license.