Nintendo has gone ahead and made the latest Wii U system update available ahead of their Nintendo Direct tomorrow morning, offering up a number of new changes to the console.
One of the biggest changes available in the update is the ability to output the display of original Wii software to the Wii U GamePad's touchscreen. Sadly the GamePad can't be used as an actual controller, with a Wii Remote or Wii Remote Plus still needed to play games but the convenience is definitely noted.
Other changes introduced in Update 4.0 include USB keyboard support, a new SpotPass option that will automatically download demos of recommended software, ability to access the Friends List directly from the Wii U home screen and the option to allow your Nintendo Network ID to be used from other devices, like a smartphone or PC.
The long-awaited Summer system update also brings stability changes to the system, decreasing load times between menus and decreasing load times of games. For full details on how to update your system check out the following link
and find the full changelog over here