The old games should work, using the old Wii controllers.
The games don't show up just by popping in a disc. You have to run them by first launching them from an icon on the home screen. That seems to confuse some people.
You won't be able to use the giant Wii U game pad with them.
Online play for Wii games is now disabled.
Saves for games that have no online component can be transferred via SD card. If there's so much as an online leaderboard, the saves will not transfer this way.
There's a painful and long Wii-to-Wii U migration option for virtual console games, but beware that it wipes your Wii in the process and you need an uninterrupted Internet connection throughout the process or it could hose one or both of your devices.
Edited 1 time(s). Last edit at 05/24/2014 01:24PM by Chakravartin.