I have an idea for making a Modern Day Mod that would change the civs to modern ones, make the leaders modern ones, and change the UUs to suit the civs.
I.e. Russia is still Russia, but the leader becomes Putin, and you change his traits accordingly.
USA gets Bush, bring in Australia as a civ, give them John Howard, bring in Venezuela, give them Hugo Chavez. China gets Hu Jintao. England gets Tony Blair. France gets Segolene Royal or Nicolas Sarkozy. You get the ideas.