It's nice to see another Cassandra thread up again. I think the problem is that we already know so much about her, like Varric, that there isn't much to discuss that has not been discussed already, unlike the 'new' companions like Vivienne.
She's certainly the companion I'm most interested in at the moment though. I really liked her in both Dragon Age 2 and Dawn of the Seeker, and I've been hoping she would be a future companion since I first finished the second game.
I really, really hope that she is an LI because it is something we have not yet seen in any Bioware game thus far, and appeals to me in a way that other female characters in dragon age haven't really so far. A female warrior who is hot blooded and short tempered but also focused on order and control. I much prefer this to the more meek, laid back or conniving female LI's we've seen in the previous games. Hard headed, blunt and tightly-stung are what I'm hoping to see.
My Inquisitor will have a very interesting relationship with her because I normally play a "chaotic good" kind of character, so I expect a lot of arguments over trivial differences in approaches, but ultimately both just trying to do good.