I believe eyetoy didn't catch on because it was a peripheral without the support it needed or the technology to tap into its potential(it had limited ability to detect movement). The next eyetoy at E3 showed the guy with two cups "pouring" virtual water from one cup to the other.

I agree it could come down to an decision about whether you want to move around or not but I'm guessing Nintendo would make it so you could play with the new controllers or with a gamecube controller if you prefer.

In my opinion if someone doesn't do something to advance interactivity than I am going to be bored with every new game. Honestly how many first person shooters can you play without getting sick of the whole experience. I guess some people will never get sick of it.