I have found very simple solution on how to access YouTube videos that require Flash using HTML5 player. Although front site may not support HTML5 video player, YouTube usually allows to embed videos to other sites, they also should use WebM codec developed by Google. If you have a video that does not work in HTML5 by default try to run it in embed player by URL modification – replace “/watch?v=” with “/embed/” and it should work! :-)

Example: http://www.youtube.com/watch?v=M84Y6VXAIaU -> http://www.youtube.com/embed/M84Y6VXAIaU