Here are some quick test renders on a flat planet (exaggerated displacements, no GI). The texture files it creates would certainly be useful for objects in TG2. Looking at the way the preset textures are created is also useful for getting ideas on how to do some of this in TG.
Diffuse image to Colour function
Normal image to Displacement function
Emissive image to Luminosity
The only thing you have to do is swap the green and blue channels in the normal image... or just use the blue channel. This can be done in an image editor or in TG (see screengrab). Oh... and there is no indication of whether the displacement is positive or negative... (cedar was positive, lava was negative). It's not a true displacement map as such so it's only going to work on some textures.