Here is a couple of snippets from TV Guides Interview with Michael Emerson.
TVGuide.com: So we have now learned that Ben was born on the island, and is as loathe to leave it as much as Locke is. Michael Emerson: Yeah... what's interesting is in neither case do we know why they're so attached to the island. Interesting.... TVGuide.com: Terry [O'Quinn] and I talked last week about how Locke considers the island itself an entity to be reckoned with. Emerson: Yeah, the island has "life juice" for him. Suddenly, all the things he dreamt of being, he now is. He's a leader of men, a fighter, a hunter....
TVGuide.com: It seems like no matter how many new things we learn about Ben — like, that Alex is his daughter — he remains so enigmatic, leaving us hanging on his every word. Emerson: It's a good character, yeah, and it is loaded in the way you're saying. When characters have more going on than the audience is privy to, it sort of raises the stakes. It makes it a little juicier, I think. A good play works that way.
TVGuide.com: Plus, Ben is such a BS artist that even if he does tell us something, we can't always believe him. Emerson: He is. Partly that serves the show's agenda and partly it serves Ben's agenda. He clearly is such a habitual game player that it's second nature. Sometimes he probably barely knows [the truth].
TVGuide.com: Have the producers given you any sense of the bigger picture here? Emerson: We don't usually talk about the story, but I know there's some big stuff coming up. This renewed battle of wills between Locke and Ben is the sort of big story that carries us through to the end of the season.
TVGuide.com: Reflecting on the past half-season or so, I sometimes wonder if we've in fact learned too much about the Others, at the expense of their mystique. I know some fans gripe, "We aren't getting enough answers," but.... Emerson: That's what you keep hearing, but I worry about it, just as you say. I think that inevitably, and the writers have promised and I am sure they intend to deliver on a swift and logical wrap-up to this story, so apparently to reveal the backstory of the island is part of their überplan, and it must be necessary.
TVGuide.com: Are there any other big reveals coming up? Emerson: Oh, there's huge stuff....
TVGuide.com: Are we going to pick up this week with the reveal to Locke that his father is on the island? Emerson: Um... it's going to be referred to obliquely for an episode or two, but you're not going to get right back into that as our main theme for several episodes. But when we do, it will be with a vengeance.