I would like to (eventually) see a movable capital city.  Something like a general, who, if killed, would eliminate you.  Even further, If you could give that "token" traveling modifiers and token-specific continents.  Even further, if you could have more than one of these tokens with different customizations, a number of new game play options would be available.  I know this isn't exactly top priority, but I wanted to see what people thought.