Same for me. Bioshock was one of the few games that actually compelled me to play through it. With Half Life 1 (and now Half Life 2), I played a little bit, put it aside for a couple years, then finished it. Great games, but I guess I wasn't drawn into the story or feel of it as much as Bioshock.
*POSSIBLE SPOILERS FROM TRAILER*
Looks like you play a Big Daddy (or the previous protagonist in Big Daddy armor, depending on if we saw the prequel or sequel footage) in Bioshock 2. Check out the sweet rivet gun and drill. It also looks like we may revisit Cohen's lair, considering the enemies we see in the second part of the clip. We may also be dealing with a rogue Big Daddy in the first part of the clip, except Tenenbaum refers to it as a "she;" this development may point to why Big Daddies are only male and not female.
EDIT: Watched the clip again. The female Big Daddy is a Big Sister apparently. And even though the second part of the clip shows Fontaine Futuristics as the locale, I still think the enemies you fight resemble Cohen's footsoldiers: bunny ears and some plastered Splicers.
*END POSSIBLE SPOILERS FROM TRAILER*