While the last season ended with everyone thinking they would get off the island, I did not think it would happen at this stage in the story. But based on that ad, it seems they might do. Which will be interesting, because it will result in even more fragmented episodes - events for those people that leave the island, events for those that stay on the islands, as well as flasbacks/forwards. It could be an interesting challenge to keep control on these elements. I'm looking forward to seeing how they do with that.