Hori is making two Super Mario Bros. controllers just in time for Super Smash Bros. for Wii U. These look like GameCube controllers, but they plug into a Wii remote controller. Hori says they are compatible with Super Smash Bros. for Wii U and will work with Wii games as well so you could use this for Super Smash Bros. Brawl too.
These two controllers have a larger d-pad and a turbo function. Turbo has three settings 5, 10, and 20 button presses per push. I guess that will be useful if you want to spam fireballs or if you find a Super Scope.
Each controller will retail for 2,980 yen and will be available on December 6.