Well I personally would highly doubt we can count Ben out just yet.. remember, John Locke was shot by Ben once and the island spared him, and we know that at one point Ben was in good graces with the island. Or perhaps this is when the "hostiles" find him, and he begins to be integrated into their culture. Also, Jin is currently unconscious near where Ben was shot, maybe he wakes up in time to get him back to the barracks and get treated. My hunch is, this event wasn't supposed to kill off Ben, but maybe explain his character. Maybe all this time he knew who Sayid was, and remembered being shot by him as a child? This season seems to be all about examining the effects of the flow of time.
For example, when Charlotte passed, she told Daniel she remembers a man approaching her as a child and telling her not to return to the island, and that the man was Daniel. Yet, Daniel has no recollection of doing this, implying it hasn't happened in "his" time line yet. This is why, in the current arc, Daniel is M.I.A. When he first arrived at the Dharma Initiative, he catches a glimpse of Charlotte as a child, and starts muttering something to the effect of "I'm not going to tell her.. not going to tell her.." I assume he left Dharma so he wouldn't be tempted, it seems like he is trying to change the series of events. But as Desmond once said, history has a way of course correcting itself.
Another example is the compass Locke has. Where did it truly come from? We first see Alpert give it to Locke in the present, but then we see Locke give it to Alpert when the island was situated in the 50's, to prove he is from the future. So who gave it to whom first, did Alpert have it in the present because Locke gave it to him in the past? Or is it the other way around?
Time travel is fucked up, is the bottom line here.