I've got to say, if you can't use the motion sensing at all while sitting down, that does cripple a lot of the useful UI demos they were showing off. For games, it kills the idea of playing a game like End War, or standard games that augment. Even Forza ... Would you really want to stand up to play Forza? They better hope there is enough good content to make you want to stay on your feet if conventional games are mostly ruled out.