I love to go to the movies and enjoy watching previews. It is fun to anticipate a movie that will be in theatres in a few weeks or months.
On the other hand I am sincerely grateful that my life didn't come with previews. I might have become frightened by some of its parts and been unable to appreciate how awesome the "feature presentation" has been. My life adventure is a true blessing.
I will leave looking into the future and crystal balls to others, no previews needed.