Update: Nintendo has since given an update on this, saying that the GameCube Adapter will ONLY work with Super Smash Bros. for Wii U, and that previous information it would also be compatible with Wii Classic and Wii U Pro Controllers was a mistake.
Original story: The GameCube Controller Adapter for Wii U will support games that use the Wii Classic Controller, and Pro controllers.
The upcoming peripheral allows for four GameCube controllers to be hooked up to the Wii U console using two USB ports, with the main game that Nintendo intend players to use being Super Smash Bros. for Wii U when the action heats up this November/December.
However, the GameCube controllers will also be compatible with "all games supported by the Wii Classic Controller, Wii Classic Controller Pro and Wii U Pro Controller." The adapter will retail for £17.99.
What games will you use classic GameCube controllers with?