The whole "multiple timelines" theory is really interesting, and I've at moments wondered if that's what's going on. If this is the case, their approach to it has been pretty cryptic thus far and they'll have a lot of work to do in order to resolve all of these loose ends neatly.
I'm half expecting a sort of Lost situation where we're still left with a lot of big, unanswered questions when the series is over. But we'll see.
In any case, I still find it pretty entertaining.