AReddit user has modded SimCity to support offline play which contradicts EA and Maxis’ statements that the servers were really vital for the game.
The game only works this way via the debug mode and the modder has also been able to create highways out of the City limits. He has also been able to make the game show the real population count and disable the disconnection timer.
How it works currently is that if you play the game for 20 minutes while being disconnected to the servers the game will kick you out to the main menu and this has now been removed. However, saving the City isn’t possible yet unless you reconnect back to the server since the syncing process is vital for now.
Once the entire modding community gets their hands on this method the game could be fully blown open and may also result in some interesting situations because this could mean the publisher and developer lied to everyone.
Of course everything isn’t clear yet, and we still don’t know what actually happens when the game is connected to Maxis servers except the extra computations (proved false) and saving.