Hopefully that means Colleen may still voice a character in the games, maybe even a protagonist.

I've seen rumors a while back that she is Vivienne VA in the PAX demo, but I do not really see hear it.
On cassandra, if there's still be companions specs, how do you think hers would be like?
She has a warhorn taunt* ability and a Seeker/Inquisition war banner buff ability in the PAX demo. Neither of these fit the warrior class as we know it from the previous games and these ability are thematic. I suspect the companion specs are coming back because of this. I can see her having a weird mix of Dragon Hunter and Seeker. Unfortunately, it harder to guess what is in it. Right now, Dragon Hunter seems to be tankish with the taunt, but Seeker seems to be support/buff oriented.
To people who believe that Cassandra knows nothing about hunting dragons, I suggest you watch DotS, she kills a few in it and comment on how her brother was the best at it in the family. Also, she does bark orders a little everywhere in the PAX demo, at the end against the dragon she actually says "I'll grab his attention".
*I remember reading when the demo was released that the warhorn could force dragons to land too, but do not take my word for it.