Well it's the NiGHTS: Journey of Dreams conundrum, isn't it. Hugely offbeat, hugely loved game gets token sequel that semi-tries to liven things up with motion controls that only "philosophically" make for more natural, dynamic interaction.
Motion controls as they are today can definitely be used to great effect, but there's still something decidedly mechanical about them, which is in stark contrast to the romantic ideas these developers/creators get when theorizing about them.
I have no doubt that Kinect on paper and in the way that Mizu thinks about it is a major step closer to realising the original intent with Rez, and as such, Child of Eden is a significant "sequel". Of course, in reality, the motion controls implementation may fall flat, NiGHTS 2 style, and what you're left with amounts to little more than a re-run.
A really pretty, really awesome sounding re-run that'll still make me pee my pants with excitement, admittedly.