Fog of war would rock. I helped design Victory (If anyone's played it here) and that was very similar to Risk/Axis and Allies with the major difference being fog of war.

You know other types of units would be cool too. Air, Ground and Naval units could be adapted to the system already in place.

It would be nice if there was a way that you could admit defeat in the game. I would assume that all of your armies would turn into computer pieces and that you would take a points penalty, but it would be handy.