You won't though or at least they won't be very good. It'll be games that you normally need a pad or another accessory with like the ones you see in that demo. There's a reason that the best games for the Wii have limited motion control.
Yeah, at least the Wii had some great games out of the gate. It's going to flop if they don't have a signature game to sell it on. They aren't going to sell it to families because they either have a Wii or don't have a system at all in which case it would be more likely they pony up 250 bucks for a Wii with additional controllers rather than 350 dollars for a 360 with additional controllers. It might be different if there was a game that really showed the advantage of the Kinect over the Wii but there isn't. The only people Microsoft can really market this to right now are 360 owners w/o a Wii and if they don't have a Wii they probably aren't interested in dropping $150 dollars for motion control.