Three points (I posted a bit of the first on the Comments section), the first one has to do with the name being applied to the dude on the beach with Jacob (who I agree Christian seemed to be "serving" - I say that because I believe there is an element of that person duplicated by the Monster in there). Second, I agree that bit with Ben seemed a bit of a retcon (though note he did acknowledge he received orders from Jacob, just not having actually seen the guy). Finally, any claims I make about the Monster in here, I'm not refuting that Black Shirt guy has control of it, just that we have seen the Monster can be "summoned" in at least one episode (The Shape of Things to Come) so there seems to be evidence that it isn't simply that one guy, but a tool for that one guy to operate.

1. The scene of The Incident was very familiar. Why? Because we've heard the noises before, of the crane and those rattling chains, of people losing arms and that roaring magnetic warble, and the image of people being dragged into holes. That is the actions of the Monster ina nutshell. You see, the Incident wasn't just the drilling into pocket of electromagnetic energy, it was drilling into a cage of energy containing an ancient force (the same force that Anubis was depicted as being at odds with) that had been trapped. Then an Atomic Bomb brought it freedom. That freedom was the 'merging', if you will, between this ancient force and the bomb's energy, imbuing the Monster (or perhaps even sending it back in time with) a more tangible existence (it always possessed those abilities of taking forms of absorbed people and scanning people's minds). We've seen Eko get pummeled as if he were lifted by a crane, we've seen the pilot get lifted up onto a tree, we've seen a chain drag Locke and Montand's into hole's (with the same sounds as in the Incident). The connections probably go on and on. The best part is, Locke described the Monster as being "beautiful". Is this because Locke recognized in it a weapon? If so, is Locke an Adrian Veidt character with Rorschach sensibilities? (Locke of old saw the world in very Dichtomatic terms: Man of Science/Man of Faith, Hunter/Farmer). Could the final endgame of Locke (now imprinted into the Smoke Monster though without absorbing the body somehow like with Yemi and Christian) bring new meaning to the subtitle to Homeward Bound 2: Lost in New York (as well as Daniel Dae Kim and Michael Emerson's visions of where they would set Lost if not on an island) as he brings the Monster off Island to bring some SmokeyJudgement Sensibilities to the world at large, in an attempt to subvert the fated end of the world ala Veidt from Watchmen?

2. Second, I am not calling the man on the beach with Jacob Esau. Why? Because its a rather silly name to give him as it has very little reality to it aside from the neatness of the biblical brothers. I understand Esau was respected as a Hunter and Jacob as a Tent Dweller (and Jacob had a son named Benjamin). But there isn't any real depth there, as far as I see.

 I will call him Moses instead. The actual conversation they had hinted at Jacob wishing to maintain a comfortable, slow measured pace to preventing the end of the world, and Moses Guy wanted to have a quick fix, a "loop-hole". Well, Jacob may be allegorically closer to his biblical namesake, Moses guy doesn't have to be his brother. Moses led the chosen people out of Egypt. Egypt has a cyclical nature due to its relationship to the Nile (The Island). This is closer to Moses Guys's intention from the opening, that is freeing themselves or the world from the cyclical time loop they are trapped in. Maybe in this allegory, Jacob is just the half of Moses that is enjoying being an Egyptian prince. Also, I found Jacob not speaking with a older style of speech strange. Thus, I am going to posit that Jacob is in fact a time traveling Aaron (possibly relating to my third point). Physically, he's totally there, it lends itself to the conversations had about Aaron in the past, and while I don't believe these two brothers, I think the reference to Locke later in the episode by Ben as "Moses parting the waters" is a hint by the writers to Jacob's true identity.

3. I read a theory that 815 was never supposed to crash. But Aijira 316 was always suppose to land with several of out Losties, including Aaron. I believe now more than ever that to be true. I think 815 crashing (which Jacob hadn't seen yet when on the beach with Moses guy) was Moses Guy's "loop-hole". With it, the Oceanic 6 (minus Sun, I'm guessing) arrived earlier than they were expected (see the state of the Runway when 815 crashes versus 316 landing). That is why Jacob had Ben sit on them, rather than exterminate them. Then, when Moses Guy trapped Jacob using Christian and informed Locke (Ben) to move the Island, phase 2 was begun: rewrite the past to change the realities of the situation entirely, so course correction wouldn't need to fix it (since it already had been changed in the future, with 815 crashing - though another possibility was this was Jacob's attempt to counter Moses Guy). Either way, the O6 were needed to rewrite events (note they weren't necessarily in the past like Sawyer, Miles, and Juilet were) to favor Moses Guy or Jacob (whoever controls Christian) and permanently alter the timeline or maintain it in a last ditch effort by Jacob. The biggest result of 815 crashing was Aaron (aka Jacob) not arriving on 316, thus never going back in time to maintain the loop. Moses Guy has ended the loop. Things have changed in the 2007 we have seen, and Jacob can die. And who are "coming"? as Jacob mentioned. It is the original 316ers, meaning either his last ditch plan with Jack and the bomb reset things or they represent the endgame between these two, but now without Aaron present. I'm confusing myself, but there is something here, I swears! Part of this point was to show why Jack was not "on the list", I think.