Since Blender 2.78 cycles material texture nodes are working in the BGE.
To add them switch to cycles and add them then switch back to BGE.
Point Density and Sky Texture are not working.
Test file: MaterialTextureNode.blend (127 KB)
Woah… not home right now to test this but does it work properly in runtime?
Sure. That works at runtime.
nice! can’t wait for dynamic reflections and probe grid reflection grid and frensel node in the glsl node graph 
(we can have real pbr then using glsl nodes right?)
The fresnel node (input->fresnel) is also added and working in the BGE since Blender 2.78. But fresnel was never a problem because it is only the dot product between normal and the view.
There are some other nodes which adds a shader now (like combine/separate XYZ). But I only wanted to inform out the texture nodes in this thread. Because some of them atm. has only a dummy shader (Sky Texture rgb = 1.0) and I haven’t checked every node.
(we can have real pbr then using glsl nodes right?).
No. To simulate roughness you need to blur the real time cube map texture. Or better use the lod textures. At the moment we only can use a rough normal map to blur a real time texture. Which doesn’t look as good.