I think they played it safe and very specifically chose not to throw us any crazy curveballs, as those kinds of endings to shows have had disastrous consequences on the show's legacy with it's fanbase in the last ten years. Lost (who's ending that I decided I liked after about two weeks), Battlestar Galactica (which was very polarizing) and The Sopranos and Star Trek: Enterprise (which were almost universally condemned as horrible ideas) are examples.