Personaly, im not really sure. I can see the pros and cons with both things. The good thing about being a prisoner to be set free is that you can pretty much come up with exactly the bagground story you want for your character. He dosn't need to be some psychopathic, murderous, skooma addicted rapist to end up in jail. There could be so many different reasons for him/her to be there. On the other hand, i really feel the origin stories in Dragon Age: Origin gave you the oputunity to see things from very different viewpoints and really feel the solidarity with others of your kind, more so, than in Oblivion and Morrowind but perhaps, my imagination is just not that great. Ofcause, Dragon Age only had 3 races. Bethesda would have their hands full if they tried something like that but ofcause, ultimately, we are just speaking of more than one tutroials, and with some lasting effect on your character. It can limit the freedom though. I couldn't just be some nobody Rouge with eventually earn his place amoung the Grey Wardens, no i had to be some noble unless i wanted to play as a mage.
I know that Bethesda and BioWares RPG's is very different but at the same time, i can't help but feel that if you take the best from both, you would get the ultimate Single player RPG.
But what do you say?