Ok, you've asked for it. Warning: This is going to be long and boring. Warning: I'm not going to put "as an expert" behind every second sentence, because I'm not. I'm just a gamer.

Why I think DD2 should not be first/third person:
Part I: Personal reasons (this is not useful, so skip it, if you like).
I have absolutely not sense of orientation. Neither in real life, nor in games. I can keep maps of entire cities in my head, and that's normally the way I navigate: I look at a map, and then I find my way. If I'm somewhere where I haven't seen a map before, I'll most likely get lost. It's the same in games, and that's the reason I like isometric games. They're like maps. In Gothic 1 I spent half an hour trying to find my hut, to no success.

Part II: Gameplay reasons
Role-Playing games are not action games. The fights are (or should be) based on the skills of the character, not of the player. I have yet to see a first/third person RPG to solve this problem. Imagine if the fights were to be carried out like in Divinity (one click, and the rest is rolling the dices): It would look ridiculous in First person mode: You see yourself striking with your sword, you see your oppenent striking.
It's almost the same in Morrowind: Although you have to click everytime, the combat has a strange feeling to it: You swing your sword in the air, and your opponent get's hit or doesn't. It's the same in isometric perspective, but it doesn't feel that wrong there. It feels like an RPG.
It's somewhat different in Gothic, but the result is the same: Combat feels strange, and if you lose, you never know if it's because your character is to weak, or because you are not good enough (And if you make a combat system like in Gothic, Alix is going to throw cookies at you).
Another reason is the party: First/Third person perspective doesn't allow a real party. Although I'm confident that Larians AI coding ability will not result in a desaster like the persons following you in Morrowind, even if there are persons following you, they are just that: Persons following you, not a party.

Part III: Fanbase reasons
If Riftrunner is good, you are going to have a Fanbase (I'm not talking about this forum) based upon two good isometric games. Chances are that a good part of that fanbase doesn't like first/third person perspective, while the third/first person fans don't know of Larian. Unfortunately that is exactly one of the things I don't like about today's game industry: Nobody is wanting to take risks anymore, for fear of losing their fanbase. But as I don't want first /third person perspective, it felt like a good thing to include anyway. <img src="/ubbthreads/images/graemlins/tongue.gif" alt="" />

Part IV: The ideal perspective
I agree with Nem, that the perspective of Dungeon Siege is good. It's the only thing I like about that game. If the engine allows zooming / rotating there should be a key that automatically returns the view to the standard view, with north on top. Everything else would be enough to confuse me.
What I would like, though, is a more "active" camera. I think that if the character's enter a house, the roof should not just vanish, the camera should go behind the party leader, and enter the house through the door, too, and then stay at a fixed angle. This would lead (I think) to an effect of houses being like the drawn pictures of older RPGS, such as Realms of Arkania. That was just an idea, though, it could turn out to be total crap if actually implemented.

Oh well, I'm finished. I think I forgot half of the points I wanted to make, but there's still time to add them later.

"In jedem Winkel der Welt verborgen ein Paradies"