The Wii U shown during this year's E3 is rumored to be using the AMD's previous generation graphics card. The Wii U will be available in 2012. More details inside.
Nintendo Wii U is said to be using an AMD Radeon HD 4000 series graphics card. The GPU is based on a RV770 core which is capable of DirectX 10.1 and Shader Model 4.0. GPUs used in Xbox 360 and PS3 can only handle up to DirectX 9 and have Shader Model 3.0. The Wii U is about 26.7cm long, 17.3cm wide and 4.6cm thick and will come with a media bay to load in Wii optical discs. It cannot support DVD or Blu-ray disc though. The Nintendo Wii U is scheduled to launch in 2012.
More information at the official website: Nintendo