"Ever since we announced SimCity and its new regional play, fans have been asking how many cities can play together in a region. Today, Maxis confirms that up to 16 cities will be playable in a single region and since we've built the game to be a Multi-city experience, you can play those cities by yourself, with your friends, or with the rest of the world.
Here you can see a brand new screenshot from the front end of the game that showcases just one of the regions that you can explore before you start a city. Right from the start, you will be able to learn lots of things about the region: who's playing in the region, what cities are available to play in the region, what Great Works are currently in development and perhaps most importantly, what sorts of resources and advantages are available within each city space. Want to take on the role of a coal baron? Click on one of the available cities and see how much coal waits beneath the surface. Stuck without resources? Why not build yourself a Trashtopia and rake in the dough by collecting your neighbors' garbage.
That's what SimCity is really all about, Multi-city gameplay where each of the cities takes on a specialized role that can help propel the region to greatness. You decide if you want to play the entire region by yourself, invite your friends to play alongside you, or if you'd prefer to make new friends and strike out in an open region."