People have it all wrong. One of the thing Nintendo has this generation that Sony and MS doesn't is a different business plan. The controller was the first step of the plan but now has really completed step 1 and 2 (Wii Fit). Even if the other companies release a sort of Wii controller, they will still be 2 years behind Nintendo. Also, the companies won't have a 100% attach rate for the controller which may create confusion in the mind of the consumers/developers.
How many cups of darkness have I drank over the years? Even I don't know...