I didn't realise until I saw your video that YouTube now supports 720p or 1080p formats......it's what I've been waiting for
So the first thing I then tried was making my own HD YouTube video. This was uploaded as a 1280 x 720p video in .mov format (Total file size around 770 Mb) !!.
Unfortunately it still is not available as an HD video - I wonder if it has to be in 1080p format. Another thing, as YouTube limits uploads to 1Gb HD videos will probably limited to a max. duration of around 4 minutes......