Nintendo needs people to buy Wii Us. Since cutting the price further isn't an option, they need to provide an overwhelming value proposition.
They should take inspiration from PS+. That initiative provided such value through the free games that people just had to sign up. It successfully got Sony customers to start paying for online on PS4 when it was a strong point of pride that they didn't on PS3. It was possible because digital games cost Sony very little to include and their launch sales periods had for the most part already happened.
They should therefore bundle a TON of digital VC, Gamecube and Wii games. Most of their back catalogue has already exhausted its sales potential to existing customers; it will save far more money than any lost potential sales if they get a few more million Wii Us set up in people's living rooms.
Differentiate the bundles by target audience, and advertise each on TV just listing a massive amount of big games. Show a Wii U surrounded by 20+ game boxes of top quality titles and the price tag will look tiny in comparison.
e.g.
Nintendo Classic Bundle: Wii U + Super Mario Galaxy 2, Metroid Prime 3, Xenoblade, Zelda Twilight Princess, VC: Super Mario 64, Super Metroid, Zelda Link to the Past
Nintendo Play! Bundle: Wii U + Super Smash Bros. Brawl, Mario Kart Wii, NSMB Wii, Wii Sports Resort, Super Paper Mario, VC: Mario Kart 64, Super Mario All-Stars, Tetris, Pokemon GSC (Off TV Play)