Will this season really be the end of Lost?

Not necessarily:

In a recent interview with The Hollywood Reporter, exec producers Carlton Cuse and Damon Lindelof acknowledged that it was entirely possible that The Walt Disney Co., which owns Lost, could sooner or later produce more of Lost in some form or multiple forms—a movie, a new TV series, books. Said Cuse: “It’s a franchise that’s conservatively worth billions of dollars. It’s hard to imagine Lost will rest on the shelves and nothing will ever be made with Lost. Eventually somebody will make something under the moniker of Lost — whether we do it or not. We just made a commitment to this group of characters whose stories are coming to a conclusion this May.”