But I do have a question: How do Wii games work on the Wii U? Can they be played on the Wii U Game Pad?
No. You use Wii remotes like normal. The WiiU supports the wii remotes because at the moment, most games multiplayer is played with 1 person on the pad, and 4 other on remotes.
Also, I got my WiiU to system update. Add me: 8biticon