The Wii U shipped without out Miiverse, eShop, the Internet Browser, and backwards compatibility. Your console has to complete a lengthy firmware update before you can access these features. I updated my Wii U before the console launched and it took 55 minutes to download. Then there was another 30 minutes of waiting to install it.
The time to update your Wii U may take even longer now and if you start the process do not unplug your Wii U to quit. You could brick your Wii U in the process and it looks like that happened to a few people already.
Nintendo doesn’t say how big the firmware update is, but it appears system software eats up a significant portion of the console’s storage space. I have a 32 GB Wii U and with firmware version 1.0 (a stock Wii U before the update) there was 25 GB of free space.
New Super Mario Bros. U and other Wii U titles can be played without the firmware update. Unless you enjoy watching progress bars, we recommend starting the firmware update overnight.