For some reason a lot of videos that I try to watch via Airplay (from my iPad) only offer audio-Airplay. For instance, I was watching some match highlights in the rugby World Cup app and after a few seconds, the video stopped and it cut back to playing on the iPad, and the Airplay menu then only showed the audio option. I don't think it's a performance issue, since I Airplay'ed many HD podcasts in iTunes without a stutter, the videos which 'failed' were much lower bitrate. Is it some setting from the video's website/app that must explicitly say "allow video to play via Airplay"? It's a pity, such a cool feature that rarely works.