At this point, most of you already know that the Wii U will need a day-one update to have a fully-featured console. It’ll bring along Miiverse support, Nintendo TVii, Wii U Chat, and the eShop. It’s now been confirmed that you’ll need to apply the update in order to access Wii functionality as well.
Without the download, Wii discs won’t be read. You’ll receive a notice saying that an update is required when attempting to play the game.