Actual docs, fantastic!  Looks good to me.  Looks like this is now the pull request to take in and delete the other two.  I have a few small comments in here, but nothing major...

A nitpick, but I always see "flash" as "Flash".

Is it playback performance that's the problem with progressive video, or just "playback behavior"?  I assume this scrubbing/seeking comment is about the fact that you can't seek into a progressive video as done currently.  I was confused here for a second, wondering what the "performance" part of this was.