What we have learned...

1. Locke was resurrected. Okay, he's not Jacob... YET. i'm still not counting this theory out. It seems to make the most sense with how "important" everyone seems to think he is (more so than say Walt, who otherwise seemed really "important" to the island). 
   
2. Tunisia, the other side of the world (literally), from the island, is the teleportation exit, as thought.
   
3. Egypt is still related, hieroglyphics, and even allusion in flashing from Tunis to Hurley's water color of... EGYPT rather than Tunis. 
   
4. Witmore's not all bad, but don't forget that he ordered the ruthless murder of innocent people (no different than Ben). ALSO remember that Jacob (in the form of Christian Shepherd), appeared to Michael to tell him what he "had to do" to thwart Witmore's crew of mercenaries. This means Jacob and Witmore are on different pages. i'm not sure about Ben "tricking" Witmore into leaving either. Maybe, but maybe Witmore just left with his crew back in the day. Would Witmore have REALLY have been able to build such a financial empire in such a short period of time. He said "three decades" which would put him in the mid-80's when he is suggesting he left... when exactly was Penny born? i smell bullshit.
   
5. By the way, Ben came to kill John all along. He had those cleaning supplies WITH him, which we know from the motel owner in a previous episode saying that he heard a scuffle and shortly after he checked on him and found Locke dead. This means no time to run out and get cleaning supplies. Ben just wanted Locke alive long enough to find out what he knew. He found out that Locke knew a TON and then it was time to off him. In any event, Ben seems to know that if John died "everything" would be messed up. This could be allusion to Locke being Jacob in the future (remember there are two more seasons to go, they ain't giving all of this away yet). This too could be why he says he will miss him in such an endearing way. 
   
6. Oh so you think tonight's episode proves me wrong about Christian's image really being Jacob? Let me explain something to you: If Christian was resurrected on the island then a few things:
   

a). Why didn't he talk to Jack when he could have just as easily as Locke talked to these passengers once resurrected?

b). If he was physically resurrected and thus time-warped with the rest of the crew then how in the Hell would he have appeared in that SEALED well cavern with Locke? Just because he was time-warping with them doesn't in any way explain how in the Hell he would have gotten down there! That's absolutely ridiculous.

c). If he was resurrected (like Locke), then why in the Hell would he know all this shit AND why would he have popped onto that tanker (read that "How in the Hell").

d). If NOT physical, and instead a ghost, then how/why would a ghost have popped BACK in time with Locke to be in the SEALED cavern? Also, WHY would being a ghost make him know about this stuff? That's a bit of a stretch to presume near-omniscience for Christian Shepherd's ghost (including apparition on the tanker). That's because he's not Christian Shepherd's ghost unless the writer have suddenly taken a liking to multiple holes in their plots.

e). Christian that Jack saw while OFF the island? Could have been hallucinating LIKE the other doctor claimed. Could have also just been Jack's actual dad's ghost. We have to differentiate between Christian ON the island and OFF. Two different things.

So is Jacob possessing Christian's body (since it was missing in that cave that Jack found it in)? Probably. It could be that Walt's apparition was actually Walt dreaming of Locke. Locke said Jacob saved him, but perhaps Jacob came AFTER that. We never actually see either save him. Remember, by the way, that Hurley sees Christian in Locke's cabin, then someone else pops up and he bolts. i'm right. That's all for now.