Only Super Smash Bros. for Wii U Will Use New GameCube Controller Adapter
Nintendo has released news about the GameCube Controller Adapter for Wii U. It appears that the new peripheral will only work with Super Smash Bros. for Wii U. This comes as sad news, as this confirms that your classic GameCube controller won't be able to be used with other games such as Mario Kart 8 or Wind Waker HD. Very odd considering that both of these games would both handle well with standard controller input.
It is unclear at this moment as to why the adapter will only be compatible with Super Smash Bros. for Wii U. The adapter simply changes the form factor of the GameCube controller's input from its classic shape to two USB inputs. This leaves only input drivers installed on the console to understand inputs from the controller. It shouldn't take too much work to have the same inputs for Super Smash Bros. work on another game such as Wind Waker, as they are both playable with the similar Wii U Pro Controller. On a good note, this does leave the possibility that Nintendo will open this peripheral to other games in the future.