Well maybe it’s possible already in blender 2.5 to render all materials in’ wireframe’ but i’ve written a little script to do that.
Maybe it could help someone.
So the script sets all materials in ‘wire’ or ‘surface’ mode. In ‘wire’, it deactivates the textures and reactivates it in ‘surface’ mode.
It’s just as simple as that :
mat = bpy.data.materials for m in mat: m.type = 'WIRE'