It's time to dust off those old wireless Wavebirds, because the Wii U version of Super Smash Bros. is going to be playable with GameCube controllers.
Nintendo has recently Tweeted that it will be releasing a USB GameCube controller adapter to work with the Wii U version of Super Smash Bros. This adapter takes up both frontal USB ports on the Wii U and will let you hook up to four wired controllers in order to get your smash-on.
It might be worth it to look for some wireless Wavebird controllers and to start stockpiling AA batteries. Unfortunately, it is unsure whether the Wavebird wireless ports would fit or even work with the Wii U GameCube controller adapter. Nintendo has yet to comment as to whether or not this adapter would work with other games, such as Mario Kart 8, which would probably be a bit more comfortable than using the massive Wii U GamePad.
Super Smash Bros. will be launching this winter for Wii U, while it's Nintendo 3DS counterpart will be debuting later this summer.