One thing we are doing is were not gimping the builder anymore. Builders typically went tall in Civ V. Were now, with local happiness, you can actually have a wide empire and be a builder at the same time. You may not be super technically proficient, but youre going to super cultural and deep into that civics tree at the same time.
Global happiness is a thing of the past, replaced by local, city-based happiness levels. As Shirk described, global happiness often got in the way of expansive empires and those going for conquest or culture victories in past games. With local happiness, the only thing stopping you is finding the right spot to put the next city. You can put a city in a desert to grab iron, and know it won't grow much. The people there wont be very happy about it, but its not going to cause your whole civilization to go into disarray. If a city is unhappy it won't grow as fast, and drastically low levels can lead to rebels "burning everything in sight," but it won't be a nation-wide issue.