Yes it's that time of the year. Let's all pretend we can still add a feature or two to the game. What features would they be? Here's my list.
-in-depth diplomacy. Perhaps #1 on everyone's list here. Let's forget about the past. RTW's system was shallow. Let MTW2's diplomacy resemble something along the lines of Civ's. I want factions to take my previous decisions and their current status in account. I want them to do sensible things; accept ceasefires when beaten or overstretched. Crush me when i am weak and make smart deals when it serves a purpose.
-make agents powerful again. Let's have agents that really make a difference. A marriage between your princess and the Byzantines should be a major boost to your relations. Spies that reach a certain level of subterfuge should get more abilities. Let them report on your enemies plans, troubles and hidden agendas. Have them say new things like 'General Louis de Beaufort of the French is disloyal he might be tempted if we encourage him to rebel.' Basically add another layer to the game by subterfruge. Give agents plenty of functions they can preform under specific circumstances.
-lots of turmoil. Make the game as tumultuous as life was back in the days. Give it lots of heretical uprisings, faction emergences (Huns, Vikins, Swiss et cetera et cetera) which can bring you in a tight spot. Script those a losely as possible to surprise a seasoned player. Make generals rebel often again and give us the option to change kings.
-Pillage and sell. Bring back the sytem of killing or selling hostages. Better still; expand on it. Implement nobles that are willing to join your army after they've been defeated. Give us the opptunity to completely sack a town or city; burn all the building inside.