I hope they expand the clothes, physical looks, hairstyles, etc. a LOT.
I feel like I have much more control over my troops in EU3, from assigning generals to troop movement. Yeah, the flanks are nice, but I've not a clue how to control them or the generals.
I hope they are in order; Orthodox Religion expansion, Swords of Islam type expansion for Pagans instead, more traits and historical accuracy and finally upgrading combat