Dragon Age: Origins is a great single player role playing experience. I can see myself replaying the game a lot of times, trying out the various origins and exploring the choices I can make as a character. But mainly because I think the game has legs and because of the fact that BioWare will surely release further content for the universe, there are a few small issues that can annoy players and only become more apparent the more people play.
First off, Dragon Age needs to make sure a system is implemented that allows players to actually establish a frontline. I cannot accept Hurlocks moving between my two tanks to assault my mage even if they are positioned so close to each other there are no pixels left between their selection boxes.
The first system that springs to mind is the Attacks of Opportunity from Dungeons & Dragons, but that system is widely known for its complexity. In a game that throws a few very hard fights at the player even on Normal difficulty, I need to actually protect my precious spell casters in an efficient manner and the current threat system alone does not allow me to do that.
Also, the game needs, at least on the PC, a way to toggle TAB permanently on to see the various interactive objects strewn through the levels. Pushing W and TAB at the same time to get through the levels is pretty daunting and a toggle would be the best way to solve it.
Finally, Dragon Age: Origins badly needs to tell players more about the underlying mechanics of the combat, with resistances, dice rolls and combat actions better explained. I understand that a lot of players do not want to actually know about the numbers and the resistances and the dexterity modifiers but there's a big crowd of players who want to tweak their experience and could really appreciate reading all that data.