*SPOILER WARNING*
One scene cut explained that if Calypso had greeted Davy Jones after his ten years of ferrying dead souls, then he would have been freed of his duty: in turn, Will is freed of his captaincy as Elizabeth remains faithful to him ten years later.
*END SPOILER WARNING*
sounds interesting and:
*ANOTHER SPOILER WARNING*
William Turner III is the nine-year-old son of Elizabeth Swann and Will Turner, portrayed by Dominic Scott Kay.
He appears in the scene after the credits in At World's End with his mother, eagerly awaiting his father's return from sea after ten years. He sings Yo Ho (A Pirate's Life For Me) as he stands on the top of the cliff on their island. The audience then sees a green flash, signifying Will's soul returning to Earth.
The writers have confirmed that because Elizabeth remained faithful for ten years, the curse that Tia Dalma put on the captain of the Flying Dutchman, prohibiting him to set foot on land except for once every ten years, is broken. This allows Will to spend the rest of his life as he chooses, either at sea or with his wife and son.
*END ANOTHER SPOILER WARNING*
could mean something.