I'd like to see deployment area's disappear from the battle map and your forces have to actually march to position themselves in their order of battle.
With reinforcements arriving during the battle at various points on the map be it being preplanned or not,maybe the chance of a flank march with the better general's.
General's ability to motivate his troop's on and off the field of battle
e.g. not all troop formation's march at the same pace so with a General he could spur them on to march a bit quicker.
A better moral system where troop's could waver or even break on seeing friend's close-by rout.Maybe each troop type could have their own moral status e.g. Guards would be Elite,Grenadiers would be Veteran,Common line troops would be Trained and Concripts and the like would be Raw.
Really looking forward to this game because this was the era when nation's were uniforming their armies in specific colour's.
I wonder if they'll include pirates on the high sea's??? Could be nasty!!!