Someone said Mark was taking suggestions in this thread, so I would like to give my input.
First let me says I loved DA2 more than DA:O, and that I bought an xbox just to play DA2, so that tells you of my commitment to the game. Now let me says what I liked about it and what I hope will return in DA3:
Voiced main character. This is an absolute must. It is the reason I haven't re-played DA:O since I picked up DA2. I don't feel a connection to the Warden (I mean, the guy does not even have a name.) I do feel a connection to Hawke, and not just "Hawke," but to ALL my Hawke's. Here's to you, Nemanja, Kelly, Xander, and Eirik (my personal favorites).
All love interests romanceable by either gender. Please do not remove this option. I loved being able to romance Anders OR Fenris with my male Hawke. I know FemHawke lovers feel the same way about Isabela and Merrill. I was frustrated and annoyed that my Warden couldn't romance Alistair, but my friends COULD romance him with their female Wardens. Not fair!
An intensely personal and gripping story. I cared about Hawke and his family and friends. I was fascinated by Kirkwall politics. The huge, overwhelmingly "epic" scope of DA:O turned me off. The generic "hero goes on an adventure to save the world" Warden's story did not inspire me. But Hawke's personal struggles with his family, friends, and lover gripped my heart and made me play the game again and again and again.
Things like fighting mechanics and quests aren't as meaningful to me, although I will say that I preferred DA2 fighting to DA:O; in DA:O I felt like I just pressed a button and had to wait for five minutes for my guy to maneuver around the others and whack the enemy. Yawn!
Now, Things I would prefer y'all change for DA3:
The recycled environments, yes, of course; I didn't mind it on the first couple playthroughs, but it did get to be annoying.
Inability to swap characters' outfits and armor. I CANNOT TELL YOU HOW MUCH THIS INFURIATED ME. (Sorry for the caps, but I'm just coming off a bad/failed attempt to mod the game via my xbox.) I hate Fenris' outfit; no insult to his creators, as many of the fangirls love it, but I personally hated it. Why can't I have the option to switch it out? It's my game, right? I paid for it, right? So why can't I control it the way I want? That was one of the few things I loved more about DA:O. As for iconic looks, characters still had them in DA:O (Hello, Morrigan and her gravity defying breasts, and all the brave (crazy??) cosplayers who chose to cosplay her) But if you didn't like it, you could swap it. No biggie.
Ability to manipulate/change the narrative in SMALL ways for multiple playthroughs. I would love for very small NPCs to be different on various playthroughs, or maybe a quest is slightly different, or maybe ... you get the picture. A lot of us play these games 5, sometimes 10+ times (basically, when I'm feeling sick or depressed, I just pop it in), so changing things up would be a big help.
Okay, I've said my part; thank you for listening.