For a lower price I might give it a chance. That said, there are a few things to point out about what you've said.
First off, what I've been reading here at the Escapist says that Milo and Kate may not be coming out at all, it could've just been a tech demo, and if it is coming out, we don't know when, but we can be relatively certain it won't be with the starting launch titles.
Secondly, I loved Rez (made by the same person making Child of Eden) and it's the most tempting of the Kinect titles to me, that said, what I've read would indicate that the game is being made in such a way so as that it's playable both with the Kinect controls and without the Kinect controls, so if Kinect can't offer me anything more interesting than Child of Eden I'd probably just play it with a normal controller and save the money.
Finally, unlike the Wii, where even though you can get up and move, with Kinect you're literally going to have to be moving. So, there's an extent to which if I'm tired, I probably won't be interested in playing it. Even more so, I don't know what the space setup for Kinect will be like. My living room isn't necessarily a good space to be moving about in, so it might be that Kinect is something I couldn't play at all.