i think its obvious what is going on here. whatever happened happened and that is still true. when locke and ben are sitting on the beach talking about the hatch door, the camp is there. they point it out. so, if the plane never crashed then why is the camp there? why is the hatch door on the beach in the same spot that it was before? everything that has happened always happened. sayid rigged it so it WOULD NOT explode on impact like he said. the failsafe was the bomb. the variable in the timeline was juliet. she changed "whatever happened happened". unfortunetly the universe course corrects itself therefore she also created the reason she came to the island because of the radiation.
another thing i think is that the statue may have been destroyed by the bomb going off in the 70's. if u think about it not much would be able to topple that giant statue other than a nuke.since the previous timeline the nuke didnt go off in the 70's, the statue had been previously destroyed by some other force due to the whh factor.the statue will get destroyed one way or the other. thats how jacob knows progress is being made. the only thing that has changed in the timeline is the nuke went off in the 70's instead of when desmond turned the key. by blowing the nuke up, the swan may not ever exist. but, by doing that the universe will course correct and find some other way to get them to the island. sorry if anyone wants this to happen, but there will be no LAX. they will all wake up in present era locke and ben. jacks eye will be the first scene and he will be waking up in the jungle.
another thing i think is that the statue may have been destroyed by the bomb going off in the 70's. if u think about it not much would be able to topple that giant statue other than a nuke.since the previous timeline the nuke didnt go off in the 70's, the statue had been previously destroyed by some other force due to the whh factor.the statue will get destroyed one way or the other. thats how jacob knows progress is being made. the only thing that has changed in the timeline is the nuke went off in the 70's instead of when desmond turned the key. by blowing the nuke up, the swan may not ever exist. but, by doing that the universe will course correct and find some other way to get them to the island. sorry if anyone wants this to happen, but there will be no LAX. they will all wake up in present era locke and ben. jacks eye will be the first scene and he will be waking up in the jungle.