Honestly, as much as I like Cullen, I'm not even going into it with the expectation that he'll turn out to be my main pick for LI. I know so little about the other characters, that one could completely surprise me and capture my interest far more than Cullen. So, while I can chat and speculate on my favourites/those I'm most curious about, I'm keeping a completely open mind. Things could easily change once I'm playing through the game and witnessing how the characters interact with my Inquisitors. 
Agree! I'm suuuuuper excited about Cullen, but if someone ends up being an even more appealing LI, that's not bad news -- that's fantastic news!!
I do think it's weird when minor characters (says the Cullen fan, but he does have a LOT of fleshed-out dialogue to go on compared to others) generate these fandoms who then decide they know the character well and really don't.
I thought Dagna was adorable, for example, but I'm not going to demand that she be in DA:I "because I love her character." That'd be silly. She could be a raving sociopath for all we know about it, and I'd have no right to be mad at the writers for taking here there. 
I'm not at all interested in Cole, but he could be the next Aveline and end up being my favorite character instead of the waste of space in my party that I'll ignorantly assume he is. Who even knows, you know?
Heck, if Cullen isn't in the party, I might end up SO GLAD that he wasn't, because he's still a big deal in our story AND we get another companion to love since he wasn't taking up that spot. 