First things first: the name. This is, for all intents and purposes, SimCity 5. The very desktop shortcut EA used to launch the demo was labeled so.
The Societies part is there to denote a shift of emphasis away from zoning - painting large areas of land with broad "residential" or "commercial" strokes - and toward choosing every building in your city personally, and focusing them into smaller districts - societies. It's more about building communities of people and managing their mood than manually laying the pipework for your city's water facilities.
The idea came from Rod Humble, vice-president of EA's Sims division, and the influence is clear. Every citizen (Sim) in your city is now individually simulated, right down to the time they arrive at work. If they're mugged by a criminal - a product of your slum housing, no doubt - they'll arrive late and get less done that day.
And you can't have that. Societies is almost entirely about making sure all your people show up for work every day, and get the hell on with it. Like a lot of SimCity mechanics, it's a bit depressing if you think about it. Build a car dealership, for example, and the Sims who visit it will be +2 happy for 28 days. That's all the happy a new car gets you, apparently.
Happiness isn't productive, anyway - any Sim who's more than merely content is veering dangerously close to the euphoria-induced insanity of not working themselves to the bone all the time. You'll soon fix them, though, with an Attitude Adjustment center. Sims emerge from this stark building feeling nothing - neither bad nor good - and that makes them the ideal worker-drone.