Faction Based Masteries
What I would really like to see is a fourth choice for your masteries based on faction. This would add a lot of flavor and gaming interest to the different teams. As it stands, if you didn't see the graphics, you'd have a hard time telling one faction from the next but if you could choose to give them a flavor oriented advantage.... well...
Imagine disciplined Banner Lords able to give a little bonus to common and uncommon soldiers on their team.
Imagine undead summoning skeletons in place of dead teammates.
Imagine dwarves gaining percentage bonuses on their weapon's stats.
Imagine demons damaging themselves to up their damage dealt.
Of course these could all be new abilities for new heroes but having the ability to add faction color to my raiders would be cool.