Try more CAP's, more tech, more cruisers, more frigates........................the list can go on and on. They dont have to stop with a Diplomacy expansion. Really there is a HUGE amount of things they can add to this game to change the overall gameplay.
Why? dont need more caps, more cruisers, more friates what we have since entrentchment is fine. I doubt IC will wnt to add more things that will just complicate the current balance