Looking good so far... I have to say though, that it looks a bit too obvious that you've used the same textures on all the same buildings (ie a few of the metal doors have rust in the same places etc). Try mixing up the textures a bit more etc, add some bump mapping and watch out for stretching/tiling and the actual scale of the textures (<G> that is some massive siding!).
As for the lighting, I agree, it's looking a bit flat without any shadows etc.
Have fun working on it!
"Two things are infinite- The universe and Human stupidity... I'm not so sure about the universe" -Albert Einstein.