Season 5 was good. It looks like Jacob was good, and the survivors, Miles, Frank, Juliet and Desmond will have to team up with Bram and Ileana's group to bring down Ben, the Others, Charles Widmore, the Smoke Monster and Flocke, but no pressure.
I don't think they erased anything, because most of the fans would kill the writers if they did that and it leaves a big plot-hole; If Oceanic 815 never crashes, Daniel Faraday never comes to the island on the freighter, if he never comes to the island he never goes to the 70's and leaves his instructions on how to erase the time-line.
I think the white screen was really another time-flash sending Juliet and Miles to the present, because they weren't contacted by Jacob. That way, Juliet's alive lying in the crater from The Swan implosion in 2004. Miles is there to help her, and Dr. Chang knows about time travel now, so maybe he left clues to help his adult son.
And the Smoke Monster is at least working with Flocke (Fake Locke) which seems to be the bad guy. The Monster takes the form of deceased people, and Miles ghost-busting powers will probably fit in somehow.
The other Losties in the 70's were probably flashed to another time in the past, to tell blonde Eloise everything that's happened to them so far, that is how the white-haired Eloise always seemed to know what would happen. I think 1983, just because that would be the year Ben would turn 18 and start taking on "adult responsibilities."
Oh, and Richard, Sun, Ileana and Bram will probably try and fail to capture Flocke after they see Jacob's body, with Ben being stunned to put it lightly.
I also think family members that know about the truth, like Hurley's parents, Cassidy Phillips (Clemintine too), Claire's mom with Aaron, Walt and his grandmother, Sun's parents and Ji Yeon for a family reunion will all be coming to the island via Desmond. Maybe more like Juliet's sister and nephew fo their own reunion and Kate's mother so her and Kate can redeem their relationship, and maybe it can heal Kate's mother like it did Rose. Maybe Jack's mother so we have an older generation love drama between her, Claire's mom and the mysterious Christian.