This is really neat. I like your thinking that it could create a whole genre of software-art. I see it as being very plausible as I'm sure engineers worth their salt have seen poetic charm or elegance in expression of some of their codes.

It'd be great if a program's city metaphor by virtue of the rules (similar to Python's indentation rules) give rise to efficient/beautiful architectures. For example, for obvious reasons, buildings close to each other enjoy in-memory proximity and thus cache locality induced performance improvements.