It's been speculated around because of the options in the magic mirror. Perhaps my own fault for also reading too much into it, but I'd feel cheated out of /something/...
I was thinking about the magic mirror, too. The options for each character are very interesting, and - at least to me- strongly hint that there could be different paths for each of them.
Paths you can hopefully direct. Just saw a video on Pathfinder that you can corrupt a certain companion. What's up with the overrepresentation of redemption arcs in RPGs? Characters should have their own unique developments based on your decisions and should have a combination of: 
-Starting bad and staying bad 
-Starting good and staying good 
-Starting good and turning bad 
-Starting bad and turning good 
It would be interesting to have a companion start good and turn bad at the same time another companion is starting bad and turning good.