Well, i am still high about the movie, went to wikipedia to seach for the movie and found a page that explain what happan in the scene after the credits
William Turner III is the nine-year-old son of Will and Elizabeth 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. His existence signifies Elizabeth's faithfulness to Will and so after the 10 years Will was doomed to serve are over Will is free to spend his life the way he wants
This means that Will Tuner can go ashore and in the maybe in the fourth episode, will tuner helps jack to find the "fountain of youth"