Shouting the Dragon Shouts would be nice, but it would have to tell you how to pronounce them before you use the shout.
Waving your arms about to cast spells and strike with weapons I don't see working, at least not without a controller to work with it.
Changing items would be a massive hassle with Kinect. Say you had to do a specific gesture to get a certain spell out. Kinect would almost certainly detect it wrong at at least 1 point in time. Same would go for blocking vs attacking. it would likely pick the wrong one when you really needed the right one, but pick the right one when you could recover from its bad detection. The same kind of goes for voice controls, which were demonstrated in the vid. I don't mind it too much, other than the fact that it took a while to get out the item he needed, even after he'd said the command the swap over didn't begin for what I count as a reasonable pause, and we could see the bad recognition when he tried to select flame atronach.
If you had a menu to scroll through to equip stuff, it would just be a lot harder than using a keyboard and mouse or a controller to equip stuff. Voice controls kind of work around this, but it would get tedious, and for those like me who have others in the house when I'm playing games, I would get told to keep it down 'cause they're trying to watch TV or something.
It is an interesting idea, but with current motion controls, no. Imma wait till they become perfectly accurate all the time, don't take that delay to process what you said, and put my arms and legs as my characters arms and legs, so rather than putting one foot forward and having that as walk, I'd actually walk to walk.