Oh, happy day!
[Update: Nintendo isn't sharing any other details about the adapter other than what we know below. Hopefully more details are shared at E3.]
When Super Smash Bros. on Wii U releases later this year, it'll include optional support for one of the most beloved controllers of all time. That's right, Nintendo's found a way to bring the GameCube controller to the party.
Nintendo of America tweeted the news, along with a picture of the adapter that'll make it all possible. There's no news yet as to how much it'll cost or when it'll release. We've reached out to Nintendo for more details.
A hot topic of discussion around our office is whether or not this adapter will include Wavebird support. Apparently we all like to do our smashin' from the kitchen.