I think that the 1977 end of this season's finale marks the end of a timeloop that the Losties have been stuck in. There has always been an original timeline that has been untouched by the Losties, where Radinsky drills into the electromagnetic pocket, a hatch is built, and eventually Flight 815 crashes onto the island. At some point in this original timeline, the Lost characters go back in time, whether it be the same way we've seen this season or some other way. When they go back, it creates a timeloop.
How do we know there's a timeloop? One clue would be the fact that Eloise Hawkings knows she kills her son in the past. Her killing Faraday is not part of the original timeline, so the only way she would know is if Faraday traveled back at least one time before what we've seen on the show. Another clue would be the different "visions" Desmond has about Charlie's death. These are not visions, but rather Desmond remembering the different ways Charlie has died before in the altering timeloops.
The timeloop that I think the Losties are stuck in is the plane crashing, going back in time, and then dying in the past (Hence Richard's "I watched them all die" line). Up until this point in the show, their previous actions in the past have only created small ripples in the timeline as Faraday would put it and ultimately nothing has changed. Now the show wants you believe that main point of the 1977 finale was that they stopped the plane from crashing. I don't think this is the case. The ultimate result of their actions is going to send the Losties back to the present and therefore ends the timeloop where they always died in the past. This would explain Jacob's "They're coming" line, the shot of the eye (probably Jack's as he wakes up on the island in the present), and the "destiny found" line in the promo for next season as they can play their part in this impending war now that they are back from the past.
How do we know there's a timeloop? One clue would be the fact that Eloise Hawkings knows she kills her son in the past. Her killing Faraday is not part of the original timeline, so the only way she would know is if Faraday traveled back at least one time before what we've seen on the show. Another clue would be the different "visions" Desmond has about Charlie's death. These are not visions, but rather Desmond remembering the different ways Charlie has died before in the altering timeloops.
The timeloop that I think the Losties are stuck in is the plane crashing, going back in time, and then dying in the past (Hence Richard's "I watched them all die" line). Up until this point in the show, their previous actions in the past have only created small ripples in the timeline as Faraday would put it and ultimately nothing has changed. Now the show wants you believe that main point of the 1977 finale was that they stopped the plane from crashing. I don't think this is the case. The ultimate result of their actions is going to send the Losties back to the present and therefore ends the timeloop where they always died in the past. This would explain Jacob's "They're coming" line, the shot of the eye (probably Jack's as he wakes up on the island in the present), and the "destiny found" line in the promo for next season as they can play their part in this impending war now that they are back from the past.