Very nice Goldwell, but your map does remind me that TDM needs a better snow material (perhaps a shader), i just hope that after the GLSL render is done i will be able to donate one (no promises), i'm learning GLSL shading for my game, for example one that "sparkles" a little as the player walks around, also those roofs need something to break the edges perhaps some ice spikes/ ice stalactites. I would also use some deformed patch's with the snow material applied to break the flatness of the snow along the roof surface, like we do to ground surfaces.
My advice would also be sub surface scattering. I mean that's something I don't think we can do yet either. If we could render in SSS, it would help but you're also having to fight hard edges with patches. I'd say Vertex Blend specific materials would definitely help but I don't think enough people would want to take the time out to blend snow details on mesh converted sections.