My guess would be Kinect. Based on the interested "Natal" generated last year. Also it has more advertisement potential, it's new, different. Move might get stuck in the wii-like area, so wii households won't probably see the purpose.
In the end though, I think both will fail to get the same level of mainstream/casual exitement the Wii generated when it first came out.
"¿Por qué justo a mí tenía que tocarme ser yo?"