There are tons of tricks and methods that can be used to render cityscapes, this is just one of them. I use a 2D heightmap in the terrain generator, and replicate that over the plane... Change the camera setting, add some atmosphere, apply some materials, render a separate distance mask to use in Photoshop to create the distance blur, and that's pretty much it =P Sounds complicated?!? Thats exactly why you should study, play with and experiment from the included scene file =)
>>> Bryce 6 CityScape Scene File <<<
Now you have a scene to work with and study from..... Try different camera angles and settings, test out some of the included Bryce cityscape materials, add volume slabs and proceedurals at varied heights, or even play with some of my "Technocracy" materials and atmospheres to get you started in your mad lab experiments =)
Greatly impact the visuals, render high resolution and apply postwork, you can generate intense imagery with the greatest of ease...