Originally announced for the US and Canada, the Nintendo TVii service is already expanding to Japan (and it's not technically available in the US and Canada yet). The service launches in Japan with the Wii U on December 8, and allows users to view a program guide and supplementary information about shows.
In Japan, TVii is a partnership between Nintendo and Rovi Corporation, who will provide a Wii U-based version of its "G Guide" interactive program guide.
The TV remote control function of the GamePad, which allows you to turn on your TV and change channels, inputs, and volume, will be a ¥100 eShop download in Japan. It's free with the North American Wii U, and part of the initial system setup. It's also great.