I'm not a MS fan, but I'm persuaded that if debugged carefully and if exploited with original games made to run on it better than on anything else, Kinect could sell in the order of magnitude of Balance Board. But from what MS showed up until now, I see a wasted opportunity. Sure, MS can get things straight later, but time is already running out.
For Move is too early to say anything for sure, we must see how big is actually the market both Nintendo and MS are overlooking. Obviously Sony will try to get a small casual slice too, just to help it.
Overall I think a moderate success is possible for both, with greater opportunities if they try really hard.