For instance, perhaps this first dragonborn is doing things that are perceived as bad, but in reality, he is trying to contain some greater evil and you end up being allies with him in the final moments of the dlc. You two team up in an epic showdown with this baddie and then he basically teaches you what he knows and becomes a super powerful ally.

I'm not saying I expect this, I would bet good money that the first Dragonborn will be our enemy, but the possibility exists that he might not be. I don't know how to read Bethesda. DG was straightforward (mostly) but I can't remember all their other dlc. I think it would be cool if they were a little less transparent when it came to their major story arcs, anyone else?

No. Not really expecting a twist. Just to bring down the big bad.

DEFINETILY expecting a twist. Even Alduin had a twist to him - he was the son of Akatosh, and his destiny is (eventually) to eat the world. As for DG, there were SEVERAL fascinating twists - including the snow elves and the family of the master volkihar guy. So there is NO WAY that this is simply going to be a 'go find the bad guy and stomp him' expansion. There will be an elaborate storyline with all sorts of interesting suprises.

Yeah, of course. We don't even know the basic plot. We don't know why he is the first dragonborn, why he's associated with Hermaeus, what he wants to do, how the Dunmer/Skaal might tie into this.