The sensor bar for the six-year-old Wii is not needed to setup a Wii U console. A sensor bar is included in some Wii U packages, but you’ll only need it connected to your Wii U when you play games that function with Wii Remotes.

Remember, the sensor bar that comes with Wii U is essentially the same one that is included in any Wii package. If you want to play Wii games on Wii U, you’ll obviously need the sensor bar connected to the new console.