Just the stuff many people have been asking for some time to improve the ironclad online experience:

1) Single binary should allow for any game style from previous generations/expansions, i.e. Running the Rebellion binary I should be able to set up online matches of Vanilla/Entrenchment/Diplomacy/Rebellion games.

2) Online map sharing with dynamic map-loading: The map maker app should, on the first launch, present an EULA telling that to share the maps online, the player must agree to placing the maps on public domain or a creative common license, which allows for free distribution, reuse and adaptation.

With the licensing out of the way, any custom map which has been made available online should also be useable on an online match. If the players joining the match do not have the map in their computer, the game should automatically download it before starting the match.

Custom maps available online should have a popularity/start rating system for the players to vote on them.