Ive been playing this game for 2 days straight. Its a bit lacking in polish, but it great nonetheless and could turn into something big if the modding aspect really takes off.
As i play this game, i have a feeling more and more that although the software is a game, its also like an RPG book with a ruleset, monster tables and various locales. Youre playing a game, but you also have "in your hands" the tools to make your own adventure and story. Sorta like getting a campain book boxed in with the toolset.
I dont know how others feel, but to me this is the game's strong point and i would like the devs to edge toward that by helping players with even more tools to nurture the modding community.
So instead of a new campain for the expansion in a year, more like:
- a load of new tiles (and tile parts/objects) to make world maps/tactical maps with, a monster expansion pack with tools for easily changing the size, stats and color palette of enemies so players can easily do stuff like "Greater Ice wolf", "brown wolf pup"and Unique boss mobs (or recruitable heroes) that you equip from head to toe (Ex: Undead skeleton sorcerer, with own loot table. Made from basic skeleton model sized up and blood red tinge, dressed up with custom clothes).
Another example is say a player wants to create a new school of magic like necromancy, using a mod crystal node, if there are enough tools available the player could touch up a bunch of creatures slightly and create undead forms of bears, spiders and wolves without too much work. One of the skills of necromancy would be a passive skill that lets him resurrect a % of mobs after each battle. Thats the sort of thing that could spring up if the tools available are good enough and easily lets people create content. I know you guys just released a toolset, not saying its news to you but im egging you on 
- Tools to help players expand the spell book
Sorry if some of those tools exist already, these are first impressions.
- New tactical maps variables, traps even maybe, using whats on the tactical map to your advantage (top off my head, tar patch on floor and flaming arrow).
Im also thinking of larger tactical maps, with more tiles (if it doesnt require starting coding from scratch and not too much work).
Some way for us to link "rooms" say like you enter a cavern and it leads to a new world map (exactly like heroes of might and magic III did with underground, again if its not too much coding).
What im trying to say is id like the expansion and coming patches to have more of a boxed set expansion for a RPG bookgame feel than a strictly classic PC game expansion with a new campain, new factions and new monsters. Theres load of modding talent out there and they will probably take care of creating tons of content that makes the game worth replaying, the focus should be on facilitating this and giving tools that exponentially augments the amount of content possible i think.