far as DA:O/A goes.  What do you think worked? didn't work? was broken? and want to see?
 
personally some major ones for me are;
 
1.  Weapon Scaling redone - seriously...look at some of the bows (btw no strings on them at this day and age just reeks lazy) the handles are fatter then the persons head...same with weapon handles on some (check out ser cauthrienne (sp) sword, it's as wide as her fucking head)..and daggers?  LOL..they're almost as large as a long-sword...totally ridiculous.
 
2. Better antagonist - sure Loghain was cool and all..but the main "boss" was the Archdemon..but he/she/it took a backseat to the politics of fereldan, then in the end it was just "sigh, ok, let's hurry up and go kill this archdemon thing....I want to go fishing."  Seriously anti-climatic in an otherwise very well done story.
 
3. Darkspawn - let's drop the darkspawn are just misunderstood bullshit the whole Architect thing is trying to convey...and while we're at it.......while I think they look cool....can we either just accept that they're just orcs/goblins or redesign them so they don't look like they were ripped right out of the Jackson LoTR movies.
 
4.  More consequences for your decisions - perfect example, redcliffe...it's really dumb that you're given several choices to settle that, when in the end leaving and going to the mage tower (since you HAVE to go there anyway) makes for a happily-ever-after ending...I mean why do anything BUT that?  except if you're just RPing a douchebag...and sticking "in character."  leaving for the mage tower SHOULD have had some consequence...the village was attacked again and a lot more died....y'know..something...not this tea and roses bullshit.
 
those are just a few..let's hear yours?

My major concern was that the game felt quirky and old. I spent a lot of time with this game, and the enjoyment I got out of it far outweighed the graphical annoyances - but if there is anything I wish they would change for the next game, it'd be to polish it and make it run smoother. 
 
This is coming from a PS3 user, mind - our version wasn't very well done. I also ran into numerous game-breaking bugs that I obviously don't want in a sequel =(