i think it's a terrible idea. For several reasons... 1. It's the Wii's thing. Let the Wii have it. I like my 360's controller. To my it is the most complete controller ever made. If I wanted motion controls, I'd play my Wii. 2. It's copying the Wii. This gives it a "cheap imitation" feel. Regardless if it's a cheap rip of what's hot or if they've thoroughly developed it, it will come off that way. 3. The Japanese hate Microsoft as it is (I think it's racist BS, but that's a different conversation). Biting a Japanese console's innovation isn't gonna garner any votes... In fact, they might hate Microsoft more. Not to mention the hordes of American gamers that has a hard on for anything the Japanese like. The only positive not about this whole thing is... If the thing works as well as the Wiimote does, then those developers that like the Wii's motion controls, but wanted more horsepower, will have some place to go.
While agree its just a copy I feel that they should focus more on Europe than Japan. Your not going to beat out Sony or Nintendo on their home ground. I think why their doing this is to attract more developers. A Motion sensor controller brings alot to the table.