I've changed my mind on Morrigan...I think I was still on the post-game high. I still REALLY, REALLY want to meet up with her again, but as other people have pointed out, this might be better in a full-on sequel, and not an expansion. So I'm willing to wait.
But that said, I want to be able to talk about her to the other companions. I want to be able to show in some way that I'm still "carrying the torch."
The first time I played through, I ended up breaking up with her and going with Leliana instead, since it didn't look like anything would happen with Morrigan. After reading up a bit I realized how wrong I was, so I reloaded and finished the game this time vowing to find her, and even telling Anora that that was my plan. I want that to mean something, and not just "well she wasn't in my general proximity so I gave up." I really liked how she responded the more serious you got and the more you refused to let go. It would be such a huge letdown for all that to amount to nothing.