VGLeaks has published specifications of the upcoming Wii U console, which the site claims are now published on the Nintendo developer website.
The information posted by VGLeaks have not been verified, so it is a good idea to take them with a grain of salt. Of course, it is always intriguing to speculate, and the specs should be able to at least spark some discussions. From VGLeaks:
CPU: "Espresso" CPU on the Wii U has three enhanced Broadway cores
GPU: "GPU7" AMD Radeon-based High Definition GPU. Unique API = GX2, which supports Shader Model 4.0 (DirectX 10.1 and OpenGL 3.3 equivalent functionality)
Memory: Mem1 = 32MB Mem2 = 1GB (that applications can use)
Storage: Internal 8 GB with support for SD Cards (SD Cards up to 2GB/ SDHC Cards up to 32GB) and External USB Connected Hard Drives
Networking: 802.11 b/g/n Wi-Fi
Video Output: Supports 1080p, 1080i, 720p, 480p and 480i
Video Cables Supported: Compatible cables include HDMI, Wii D-Terminal, Wii Component Video, Wii RGB, Wii S-Video Stereo AV and Wii AV.
USB: Four USB 2.0 Ports
If the information is accurate, then the most interesting part may be the GPU and especially lack of DX11 support. However, Nintendo promised substantially upgraded graphics horsepower to enable HD gaming. As far as the CPU is concerned there is little detail available at this time, and it appears that the Wii U will not offer and exotic hardware features to set it apart from its rivals.