Nintendo has announced Wii U, the follow-up to the hugely successful Wii console.

The Wii U base unit console can display 1080p visuals via HDMI on an HD TV or wirelessly transmit video to a new non-HD touchscreen controller (without lag). The controller screen can be used independently or as a second display.

The base unit is 1.8 inches tall, 6.8 inches wide and 10.5 inches long. It will feature an IBM Power-based multi-core processor capable of outputting 1080p. 1080i, 720p, 480p and 480i. As well as HDMI it supports Component, S-Video and Composite outputs.

Wii U can produce six-channel PCM linear output through HDMI. There are four USB 2.0 connector slots and the base unit features a single self-loading media bay that will play propriety discs of an unspecified "large capacity" and Wii game discs.

The Wii U base unit features internal Flash-based media storage which can be expanded via USB and SD memory cards.

As rumoured the console will use a controller featuring a 6.2 inch touch screen. The controller also features four face buttons, a d-pad, dual analogue sticks, four shoulder buttons, rumble, microphone, speakers, accelerometer, gyroscope and an inward facing camera.

Up to four standard Wii Remote/Wii Remote Plus controllers can be connected at once. Wii U also supports the Nunchuk, Classic Controller, Classic Controller Pro and the Wii Balance Board. All Wii games also work.

Video calls using the controller is also possible, as is web browsing on the TV or on the controller.

"Wii U redefines the structure of home entertainment by fundamentally changing how the TV, the game console and the Internet function and interact together," said Nintendo president Satoru Iwata. "The experience enabled by Wii U and the new controller takes players deeper into their games, while reaching out wider than ever before to be inviting to all kinds of gamers."

Nintendo also announced Smash Brothers for Wii U and Nintendo 3DS - this is a title for the future. In terms of graphical performance demos shown range from Wii-level to games easily on par with what's available for the Xbox 360 and PS3.

Wii U is due for release between April 1, 2012 and December 31, 2012. No pricing information has been announced by Nintendo.