PS3 and 360 were said to run "DX11" shaders when they sure as hell can't, but you can get similar results by messing with things and approaching the shaders differently.
No they weren't as far as I remember. Show me a single place where this was said.
The Wii U API is called GX2. I think in previous pages of this thread, it was said to be similar to OpenGL 3.3 with tessellation support and perhaps some newer features added on. Honestly, all the dick swinging about DX10 or DX11 equivalent features probably matters little to what you'll end up seeing on screen. You can fake just about anything you want with pre-baked effects and they still look pretty good. You would need to really pick nits to even care. The PS3 and Xbox 360 ended up supporting much more modern effects in this manner than the hardware would otherwise indicate it would.