As innovative as the “Wii” is going to be (after all, you gotta be pretty innovative with a name like that), Nintendo isn't quite happy with how different it is from the other consoles and as such is accusing outright accusing Sony of stealing the idea for their motion-sensing controller. While they haven't brought it as far as a lawsuit(which is unlikely to happen), they do have a good point in that Sony dropped their originally controller design mid-development to push the new one.

"I'd love to dig up some old Phil Harrison (president of Sony Computer Entertainment) comments and say, 'Hang on a second--six months ago when we launched our controller you said one thing, and now why are you doing this,'" GameDailyBiz quoted Nintendo UK's David Yarnton as saying. "I don't know what their decision-making process is, but I think if you look back, any innovation that has come in game play has come from us."
True or not, it's easy to see what this really is, and that is Nintendo getting just a little bit scared about both the 360 and the PS3 being out before Wii (potentially). Nintendo's success of the DS won't be able to carry them much longer, and having 3 large next-gen consoles may be a bit much for some.