Looking pretty good, kriss. The best elements for me are the elevator and double doors. The background wallpaper(?) tile looks a little too busy to me, but that might just be because the foreground tiles haven't been textured yet. I'm also not a fan of the metal girder things...gradients almost never work, anywhere, imho. Your girders look far too clean and perfect, and the light source looks a little weird, the way it conveniently pillow-shades from light to dark starting from dead center of the curve.
Check out colortheory.net to see how to more realistically shade the curve there. It's incorrect, but I forget why, hahah! It's explained in detail at that site though. =D
Looking forward to seeing what this set looks like when it's finished.