Nintendo is selling digital versions of Wii games on the Wii U.
Nintendo has announced during its Nintendo Direct today that three Wii games are coming to the Wii U so far. Super Mario Galaxy 2 is out today, Punch-Out!! is coming on Jan. 22, and the Metroid Prime Trilogy hits on Jan. 29. Each game will cost half its usual price during the its launch week.
The Wii U can already play Wii disks, but it requires the boot-up of Wii Mode inside of the Wii U. These downloadable versions enables players to launch the games straight from the Wii U menu.
You can also use the Wii U GamePad to control some any Wii games that were compatible with the Wii Classic Controller.