Some of the said specs are:
Three cores (fully coherent).
3MB aggregate L2 Cache size.
Up to 3GB of main memory (CAT-DEVs only). Note: retail machine will have half devkit memory
Please note that the quantity of memory available from the Cafe SDK and Operating System may vary.
Modern unified shader architecture.
32MB high-bandwidth eDRAM, supports 720p 4x MSAA or 1080p rendering in a single pass.
HDMI and component video outputs.
Multi-sample anti-aliasing (2, 4, or 8 samples per pixel)
128-bit floating point HDR texture filtering
High resolution texture support (up to 8192 x 8192)
And while this all sounds nice and dandy, it also translates to developers having to re-do code entirely when porting to the Wii U.
The Wii U’s custom “GPU7” is also apparently quite ahead what the PS3 and XBox 360 are capable of, thanks to more efficient use of tesselation via DirectX 11.
Read the full specs here.