I hope we can make our own custom races with background information, pictures and maybe even music when entering diplomacy which we can then use online! It would make the multiplayer fantastic and allow really fun roleplay of our own created races and make each game a new experience as we try and work out how to dominate our unknown foe.
ALong with being able to send messages to actually do real life Diplomacy (Which you can simply screw them over with if you promise something later and they go along with say a war.)
Also I'd like to see more functions with the united council like being able to call an emergency meeting which other races can respond to or not. And on multiplayer it would be great to allow discussion before voting takes place haha it would be amazing!