This is an impressive little video shot with a Canon 5D Mark II and a couple of tilt & shift lenses – the PC-E Micro-Nikkor 85mm F2.8D & MC ARAX 2.8/35mm.
The miniature city effect is produced by the tilt & shift lenses and unique depth of field. The effect is particularly pronounced when shooting from high above your subject at a steep angle, which produces the illusion of looking down on a miniaturized model or toy.
If you like this effect, check out http://www.vimeo.com/keithloutit who has mastered it.