Okay, so I know that it's a little preemptive to start discussing expansion ideas, but you know what I'd love to see? Hybrid classes, just one for each combo would be nice. If you were either of the related archetypes, you could choose the hybrid class. This would only add 6 new classes to the game, but each hero would be able to select from 5 instead of just 2 classes.
Something like this -
Brigand - Warrior or Scout
Paladin - Warrior or Healer
Mage Knight - Warrior or Mage
Druid - Scout or Healer
Bard - Scout or Mage
Sage - Healer or Mage
Thoughts?