We're all pretty clear that the guy talking with Jacob at the start of 'The Incident' is the monster, and can take the form of anybody that is dead on the Island right? So all of the dead characters that have appeared on and off the Island are him? For some reason he couldn't kill Jacob and needed a loophole, which he got when he took Locke's form and convinced Ben to do it (by appearing as Alex and telling him to do as Locke says). Why did Jacob seemingly want to die and let Ben kill him? I am unsure about this proposed alternate universe thing, seems a bit far fetched even for Lost. Then again, when they first hinted at time travel everybody thought it would be shit and they did a great job with that- it really enhanced the show and the Island's mythology. I can imagine them flashing into a reality where 815 never crashed but with their current memories, which would explain how old characters make a return. Problem is that would create another 'we have to go back' scenario which would be boring considering so much screentime has focused on that already, with 18 episodes left can they afford to waste so much time on that again? The Hurley/Kate/Oceanic trailers from Comic-Con could easily just be to throw everyone off the scent of what is going on, it's happened with Lost before. Boring as it may sound I'd like Juliet smashing Jughead to propel them back to the same timeline as Ben, Sun, Frank etc (hence Jacob telling fake Locke "They're coming" before being killed) but it seems too simple. It would be great to see old characters back but remember they have always said that dead is dead- this isn't Heroes! Nobody in Lost has ever come back from the grave so if we get confirmation of actors returning it is either going to be the monster taking their form, flashbacks or a reset. What is going to be amazing is the promised Richard Alpert Flashback, hopefully showing him arriving on the Black Rock and explaining why he never ages What unexplained questions are still remaining?