I mean they’ll have plenty of leeway and I’m sure it will be discrete enough that Dragon Age 2 will be able to go on its own way and you’ll merely encounter some of the past characters but it will be interesting to say the least. Like you, I have full faith in Bioware’s ability to pull it off, especially if Mass Effect 2 is as successful as reviews would indicate.

Depending on how well that works, I suspect the Dragon Age series will use something similar.

Your mention of a canonical outcome somehow keeps making me think of The Empire Strikes Back. There could be some pretty significant changes in character choice without changing some of the outcomes.
For example, What if Luke hadn’t left to go rescue his friends in cloud city? Han would have still been frozen at the end of the movie, and Lando would likely still have gotten himself, Leia, etc. off the station.

Or even the show-stopper of Vader’s ” I’m your father “. What if Luke had said something more like ” Oh really? Let’s talk about that ” You could still have him breaking Han out, taking down Jabba, and helping disarm the death star, but all under the auspices of helping vader to discredit, weaken, and overthrow the emporer.

I suppose it’s probably also not a coincidence that the same people responsible for Dragon Age and Mass Effect are also responsible for Knight of the old republic.

I guess what I’m saying in all of this is that from past experience, I trust the writers at BioWare will pretty handily come up with ways to fit our choices (be they a rogue dwarf, an elvin battle mage, a human fighter, or etc.) into the overall story that they’re telling.