http://www.ign.com/a...uper-smash-bros
The Nintendo 3DS handheld may very well be used as a Wii U controller for the upcoming Super Smash Bros.
This possible functionality was discovered by Twitter user Kyle McLain, who tweeted the following photo, along with the message "Am I crazy, or does this say that if you connect your 3DS with your Wii U, that you can use your 3DS as a controller?" The top screen does indeed say "Connect to Wii U" and "Connect the 3DS to the Wii U to use your customized characters and use the 3DS as a controller."