I'm not sure what FFG's attitude is towards the Troll and Country battle map DoW produced prior to selling the game, but if it is considering following this model and releasing some of these in the future I think it would be awesome to really stretch the game.
Maps that have adventure seeds and event locations (moving to a particular location at a particular time could trigger X event related to the adventure, etc).
Maps that have a glut of terrain: large castles (most of the board), villages/cities, large bodies of water, complex river systems/marshes, cavern systems, etc etc.
or a Terrain pack that can be used to do some of the above...
My opinions!
Cheers,
Giles.