Well, Adult Swim just finished up Code Geass, and they sure decided to end on a cliff hanger. They didn't really wrap up very much at all...
Even still, it sure was an interesting idea for a story... yes, what if Britain still controlled a large amount of the world, and what would happen if it's own technology (the knightmare frames) were used against them in a fight to break free of the empire's control?
Bears some similarity to Full Metal Panic... which poses the question what would happen if the cold war never ended.