As a PS3 owner who is also, to paraphrase Naughty Dog, a closet Wii owner I don't have a problem with motion controls and will almost certainly invest in Sony's too if they deliver good games and tech.
I should point out I never considered myself to be 'in the closet' about owning a Wii.
Natal interests me a lot, too, although I'm more interested in hooking it up to a PC than using it to play games - perhaps because I don't have a 360, but mostly because I'm actually more convinced by it as an interface than a game playing device. Who knows though, if it really delivers it might be time to finally own all three consoles.
Try to be reasonable... its easier than you think...