@HeelX: I like the rendering (/ materials) in your second screenshot very much, looks really nice (except for the bright sky)!
Thanks, but I pass the compliment mainly towards Kartoffel, who did a great job on the lighting equation of the shader.
For the sky, I implemented a small tool to import skyboxes from other free sources of the internet:
I already found a nice dark sky and I am writing a pixelshader atm to change the skybox orientation (changing the pan of the sky entity has no effect for me?).
@txesmi: Nice! What AO-technique are you using?