No dualwielding?
I thought that was only deactivated during the demo. That's a shame, I really loved dual-wielding in DA:O. Two swords on my character meant serious business and unlimited splatter in every battle. A shame, but at least I'm in good company if mages suffer from the reductions the same way 
How did you get the idea that there's no dual-wielding?^^'
When choosing a character, the default Rogue model is dual wielding and in the short introduction you are too

And the redesign... well, it's a matter of taste, I don't really like the overly flashy approach, in character design or in animations (check out a Mage's standard attack combo, kind of over the top imho :> )
With the fights consisting of lots of smaller enemies and no overhead view, aiming the AOE abilities, especially trying to hit moving enemies with them, is a lot harder.
uh what? the AOE spells have a circle, cone, or arc indicator to aim the AOE and see if you'll hit your party members. Also, the AI is simple, just aim the spell where the enemies are going to be and it hits them. Also use the space bar to pause the game to make aiming even easier.
Well duh, should have specified a bit more:
I find it hard to judge where to aim the AOEs on distant foes, when I need to put the circle some ways in front of them to actually hit, for some reason I'm not sure how far out I'm really aiming which wouldn't be a problem with an overhead view

they definitely still get bonuses for back stabs and flanking. My friend said the backstab is almost an insta gib move against weak enemies
Hmm, I didn't notice a that huge of a difference in damage output...
The "streamlined" ability trees seem to work fine for Warriors and Rogues, but Mages got gimped somewhat...
Unless there are additional trees that have been totally removed from the demo, much of the Mages' variety has been lost.
The feel i got was they locked some trees just for the demo, the 6 they showed looked the same from DA 1 but without the "prestige classes"
Yeah they did lock some, what I'm referring to is the trees themselves.
The Entropy one for example, it's locked in the demo, but it's still possible to see that it has five main spells with one upgrade per Spell.
That tree in DA1 was a mixture of debuffs, damage spells and crowd control with a total of 16 spells and all of them were useful imho...
So which ones are in now, which ones aren't?
And some crowd control abilities have been nerfed, Crushing Prison completely immobilized an enemy in DA1, only incurs a movement and attack speed penalty in DA2[false: same for Pinning Shot, only a movement speed penalty].
Creation only has one heal spell which has a 60s cooldown (instead of the old 5s) when Regeneration was really useful in DA1, one reason I hope the Spirit Healer Prestige class is still there later on...
EDIT:
Sorry, Pinning Shot still immobilizes
