Here’s a translated summary of the Nintendo Direct (Thanks to cvxfreak):

Parental Controls

– Nintendo realizes that some parents may fear that their children may use the Wii U’s internet functionality without permission. Wii U has Parental Controls.
– Can restrict content based on user age, CERO (Japan ESRB) rating, internet functionality, internet browser, e-Shop spending, Miiverse functionality, friend registrations, videos, data management, internet settings
– Wii U keyboard input can save user input habits and predictive input in a specific database that depends on the game and user. Wii U does not save input data that you don’t want other users to know into the database.
– Miiverse settings can be turned on/off depending on the save profiles per game.

USB Data Storage

– 8GB = 7.2GB, 32GB = 29GB in terms of actual save data. Wii U uses around 4.2GB when using the system for the first time.
– NSMBU is ~2GB, Nintendo Land is ~3.2GB. So, both won’t fit into the Basic set at the same time.
– Wii U lets you put data onto a connected USB media drive.
– One USB drive at a time only.
– Cannot disconnect the external drive while plugged into the Wii U and receiving power.
– You can use general drives.
– In terms of powering the HDD while connecting to the Wii U, if you do not use a Y Cable Type drive (2 USB cables), then Nintendo cannot guarantee it will work properly.
– Nintendo can guarantee functionality if the HDD plugs into a power outlet.
– No games on USB Flash Memory due to games not running properly all the time (whatever this means…)
– Wii U will read up to 2TB only for external hard drives
– In Data Management, you must format the connected media drive. Note that this means you cannot use the drive with a PC.
– You can move data from internal Wii U storage to external USB media in Data Management and vice versa. Data on both internal and external media will appear in the menu.
– At launch, only 1 USB hard drive can be connected, but through a future update, more than 1 will be possible and you will be able to move data between them freely.
– SD Cards can hold PC data, Wii Virtual Console, Wii Ware, and Wii save data, but cannot be used to save Wii U game save data.

Backwards Compatibility

– Wii games, Virtual Console, Wii Ware stuff cannot be played using the GamePad screen, but only on the TV in Wii Mode
– Iwata: “We understand that there are people who were looking forward to playing Wii games, Virtual Console games, and so forth on the GamePad, but unfortunately we cannot accommodate those users’ expectations.”
– There are plans for a Wii U Virtual Console that WILL be compatible with the Wii U GamePad. Please look forward to it in the future.

Nintendo Network Premium

– For Premium Set buyers only
– Point service
– Make Nintendo Network ID, then login to find and user the service
– After logging in, you can see the points you have earned
– Buy with download card or download number
– Earn 10% back on purchases
– Earn back purchase points in ¥500 increments
– Points earned can be used with Wii U/3DS e-Shop, Wii Shopping Channel, DSi Shop