I love seeing stuff like this. But what really excites me is when these types of 3D models start to represent real cities. Like the ViziCities project[0]. Maybe the idea of Mirror Worlds [1] will eventually become reality.
I'm the creator of ViziCities. It's projects like this (and SimCity proper) that inspired the project and the attempt to making something similar for real-world cities. We're getting close!