Here are my wishes to see in Civ5:
1 - A few more government types like oligarchy, technocracy, popular democracy (different from representative democracy) and others.
2- No revolution in voluntarily changing civics. That, IMHO, was stupid. Revolution should only occur during high stress factors such as war weariness, high unhappiness (possibly caused by harsh civics), border sprawl, corruption, but not voluntarily.
3 - Add economic investments/takeovers in enemy borders.
4 - Spy system should be easier to utilize without decreasing other factors such as science or culture
5 - Decrease the war-bog effect - getting dragged into a war shouldn't decrease your resources to the point you can't do anything esle
6 - More opportunities to gain ground in tech race such as events, military conquering with a chance to gain an opposing tech (like it used to be).
7. Bring back other traits like agriculural and seafairing!
8 - video advisors