SimCity players with rather formidable technical skills have already started releasing a variety of SimCity editing tools, which will help game modders to create interesting hacks and custom content for the game. One such tool is SimCityPak, which aims to be the iLive Reader equivalent for SimCity 2013. It allows you to view and edit the game assets contained in .package files. This includes the ability to modify the game’s internal 3D objects, textures and scripts.
The process of creating these tools has been greatly simplified by the existence of similar tools for other EA titles. Games such as The Sims 3 and Spore use a remarkably similar internal structure, allowing the tools created for these other games (such as S3PE) to be easily ported to SimCity. If you’re a confident .NET programmer (I am, but I just don’t have the time); the open source nature of all these tools means you can join the development effort.