According to vgleaks the Wii final specifications have been leaked. The leak is supposedly only available through a Nintendo developers site (www.warioworld.com).
Here is the supposed final specifications:
“Espresso” CPU on the Wii U has three enhanced Broadway cores
“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)
Mem1 = 32MB Mem2 = 1GB (that applications can use)
Internal 8 GB with support for SD Cards (SD Cards up to 2GB/ SDHC Cards up to 32GB) and External USB Connected Hard Drives
802.11 b/g/n Wifi
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.
Four USB 2.0 Ports