Ah, that's right. I'm such an idiot during the episode when Locke mentioned Jin I thought, "So that's how Ben knew he was alive." "duh
So now we just have to wonder how Ben got ahold of Jin's ring. I suppose that also makes sense for Ben to kill Locke because if Locke wasn't going to try to get Sun back then it would mess up getting them all back for whatever purpose getting them all back is for.
So now that we know time is moving more slowly on the island (three years to the Oceanic Six, a week give or take for the ones left behind) that blows the theory that the island stopped time hopping during the Dharma era and those left behind have been living among them for awhile. Well maybe not, maybe time sped up compared to the rest of the world after Locke left. Oh who knows, makes my head hurt thinking about it.