What do you mean, "It's not even out, yet"?

Anyhow, just reading the rules, a fairly obvious expansion idea comes to mind: One time orders. You could have a unique order card for each faction, which could be used just once during the entire game, and give an appropriate substantial advantage. Here's a quick take on what that might look like -- though I'm sure these are nowhere close to balanced.

Uthuk unique order: Destroy! (#9): Exactly like Mobilize, but with a higher number. Having an extra double attack card available in your deck could be very useful.

Undead unique order: Arise! (#1) (I'm assuming you only get to use the supremacy bonus if the card's number is lower than, and not tied with, any other card you've played): The main part of this order allows a single activation/move, like with mobilize and conquer. Supremacy bonus: You get back any forces you lost in a battle triggered with this card's activation, plus you get 1 Reanimate for each enemy unit you destroyed.

Knights unique order: Alliance (#9): The Knights player may request an alliance with any other non-evil factions. If the allied players have six dragon runes, plus three for each alliance member beyond the first, then they jointly win the game.

Elves unique order: Peace (#1): Until the Elf player executes his next order card, no player may play an activation token onto any area containing an elf unit. Supremacy bonus: Receive benefits from all your controlled cities (as per the main Rally Support order), plus twice the number of influence tokens currently indicated on your dials.

Lindsey said:

Also allowing you to play it in winter to take advantage of the winter movement rules, and get the supremacy bonus. You can't do that with the regular movement orders.

Can't wait for Orcs and Dwarves and boats. The Battlemist expansion had boats!!!

I see the most obvious expansion as being most likely additional playable armies. They may include rules for 4-6 players if that also is the case.

the obvious expansion here is to add more meat to the heroes system, here's what I'm thinking.

Heroes can now join in combat, but not as unit. they lead their army by giving it bonus in combats. The bonus depends on hero stats + the items s/he's holding. heroes can use abilities or cast spells with their fatigue like in other games. you can't deal damage or rout heroes because they're not units.

if an army is defeated and it has an hero, you roll to see if you manage to capture the hero. if you capture him/her, you can decide to execute him/her or persuade him/her to join your own army, depending on the alignment.

Hero/leaders could do what Nobles did in Warrior Knights. They let you draw extra fate cards in battle, but then you have to discard back down to the number of units you have. So your hero/leaders effectively give you more tactical options. You can decide whether to activate your special ability or do a damage, etc.