Nintendo's latest Wii U firmware update is stuffed with additions, including the ability to play Wii games on the GamePad screen - although Wiimotes are still required to control them. The 4.0.0 U update is live, so you can download and install it right now.
Standing out among the various features and tweaks is the ability to plug a headset directly into the GamePad for Wii U Chat, and being able to take screenshots and upload them through the Internet browser during gameplay.
The 4.0 update also adds USB keyboard support, Surround Sound support for Wii games, the option to automatically download recommended software and demos via SpotPass, and even the ability to view PDF files in the browser, and more besides.
Check out the full update notes here