... though you can't use your Wii U Gamepad to control Wii games.
A feature to output video and sound to the Wii U GamePad when using Wii Mode¹
Users can choose to output to the TV and GamePad, or just the TV
A feature to automatically receive recommended software and demo titles from Nintendo using SpotPass
Support for USB keyboards
An option to disable use of a Nintendo Network ID on non-Nintendo hardware, such as PCs and smartphones
Support for Dolby® Pro Logic® II Surround Sound when playing Wii software
Added a friend list icon to the Wii U Menu for easier access to the Friend List
An option to automatically receive recommended software is now available under "Internet"
A setting to select which cable outputs sound is available through "TV"
Users can choose to output sound through an HDMI cable, non-HDMI cable, or both cables at the same time. Click here for instructions
A setting to adjust the hourly interval in which standby functions are performed is available under "Power Settings" when Standby Functions are enabled
Added the option to view a friend's profile on Miiverse when sending or receiving a chat request
Users can now chat using a headset connected to the Wii U GamePad
Pressing the R or L Buttons on the Wii U GamePad will skip video playback forward/back a small amount of time
Holding the R Button will speed up video playback
Ability to save username and passwords for websites that require login²
Ability to launch the Internet Browser during gameplay and upload screenshots
Added support for viewing PDF files³
Added features intended for website developers that allow the user to enable developer tools and set user agent
Improvements to system stability and usability:
Further improvements to overall system stability and other minor adjustments have been made to enhance the user experience
¹ Wii software displayed on the Wii U GamePad cannot be controlled by the GamePad. This feature only allows Wii software to be displayed on the GamePad. A Wii Remote Plus or Wii Remote is required to play Wii software titles.
² Users can delete saved usernames and passwords from the Internet Browser settings.
³ Sometimes data may not be displayed correctly depending on the size and format of the PDF file. PDF files cannot be saved.
Pretty cool, right? Too bad you can't use the Wii U Gamepad to play your Wii games... maybe in a future update? At least for the games that have native GC/Classic Controller support?