Microsoft is going to kill Kinect not only with the price point that has yet to be announced, but more importantly, at one point they have to let people play it who they can't control like celebreties and gaming journalists. Kinect seems to be lacking, otherwise Microsoft wouldn't still use prerecorded material to show it off. Price and word of mouth are going to be Kinect's demise.
But yeah, the 3DS is also a much more promising device than Kinect and is going to draw attention away from Microsoft's product.
They showed live demos of Kinect at their press conference. Try again.