One feature I want to see in Heroes VI is hero titles: by doing interesting things your hero can earn titles that get added to his name. You have one active at a time and can choose between the ones you have unlocked so far.
It's an incredibly simple feature and easy to code, but adds a surprising amount of flavor to the game. Anybody who's played the Fable games knows of it, and I was amused to even see a title system on my friend's Nintendo DS Yugioh game.
Things like Dragon Slayer(slay 5 dragons), Avenger(avenge a friendly hero), Beautiful Warrior(I don't even know what you do to get this, but I've seen it before on a male character)