Let's see, I'll just say a few new things.
New civ traits (seafaring and agricultural). Seafaring gives units faster movement, less chance of sinking out at sea, and commerce bonuses in coastal squares. Good for archipelago maps, but almost useless on Pangea.
Agricultural, excellent. Extra food in city center, extra food from irrigated deserts. Excellent for those 4-turn settler pumps.
New governments, Feudalism and Fascism. Feudalism is good for small empires. 3 gold per unit

but decent unit support, but also war weariness. I don't find much of a use for it. Fascism, worst culture gov, best warmonger gov. Communism is still best for large, spread out, corruption-ridden empires, but Fascism is for smaller, ultimate warmonger civs.
LOTS of new civs. New terrain (marsh, can't build cities, volcanoes, can't improve it at all, and they periodically erupt).
New wonders. Statue of Zeus, produces a kick-ass Ancient Cavalry unit every 5 turns for free, almost as good as Knights. Other new wonders too. New units (namely upgrades for the swordsman!).
Other stuff that I don't feel like going into at the moment. Keep in mind that there's a bug where computers won't build armies

but the AI is much improved (they actually are decent at naval warfare now!).