No ridiculous fantasy units: This means no flaming pigs, no elephants long-range cannons on their backs, and no ninja-like arcani.

Better diplomacy system: Allies shouldn't randomly backstab you even if you've been nice and given lots of money to them. Also, the whole system of protectorates needs to be redone.

More expansive map: It's good they're including Africa, North and South America and parts of Asia in addition to Europe. But I worry that almost all of the provinces will be in Europe and places like South America will have just a few provinces.

Smarter AI: Hopefully in both campaign and battle.

No one ordering you around: In m2tw, the Pope made it incredibly annoying to play as a Catholic faction- I could never expand where I wanted to. The Roman Senate was similarly annoying.