This is a present from nintendo for platinum membership users who have bought many games of Wii/DS last year.
As you know, this is a replica of the game pad of a certain game console that Japanese people call "Sauper Famicon". You know Super Famicon as SNES.
This controller is a kind of Wii classic controllers.
So it's possible to connect this to Wii controller and enjoy games of virtual consoles!