I think the others arent as bad as we think, they mention there the good guys, so there has to be bad guys right? Well, I think the people behind the whole experiment thing going on down the hatch are who they are fighting.
What I really want to know is why they chose Jack Kate and Sawyer, and not Hurley. Are they special in some way ? Maybe the others want them to join and fight Dharma with them, im clueless.