I'd personally prefer to see a setting not long after MTW finishes - 1500's -> 1700's so could encompass Spanish hegemony & Dutch revolts 30 years war through to Battle of Blenheim. It's an interesting period - ever changing alliances rise & decline of Turkey & Spain, Rise of France & English as dominant powers blah blah blah. In my humble opinion it is too cool a period not to sim with TW next. Notwithstanding that, I played the old Microprose game Fields of Glory to death when it came out & later the Firaxis Nap's sim & would salivate copiously at the prospect of any Nap's based Horse and Musket Total War!

But what I'd like to see CA do more than anything else is a Multiplayer campaign... ACW would be good for that - like that old Steve Green (??) game The Civil War which was pretty good fun MP for 1990something.