@RobNic Yes free Materials (Bump Mapping, Enviroment Mapping etc.) are planed or already implemented. By the way, a "light" material editor is also already implemented. Have a look at the second screenshot. You can change all these things, and the Shadercode in realtime. Its also planed to load skins etc. for a material.

@PHeMoX Theoretically it would be possible to edit blocks and lights. But you wont see any change because Blocks are not dynamic. You would have to restart the game and build with "build map". This would be nonsense.
Editing Lights however is more interesting. Although i can not edit the old light, i could set a new Dynamic Light. I'll have a look at that.

TripleX