Yes, there was a leaflet in the DVD supposedly that said that after the movie was completed it was decided that Will's fate is changed on whether or not he must ferry souls every decade for some unknown reason. The green flash when he leaves Elizabeth for the first 10 years signifies he comes back from the dead after removing his heart and giving it to her (imho) and the one after signifies of course that he stays and probably gets his heart back.
-bc he is faithful, which is an irregular. There's no reason he should have to do that. I believe it's all just at gunpoint. The reason Davy Jones could not step on land every 10 years was because he was so ferocious he did not need to imo: he waited 10 years to try to reuinite with the goddess. For no known reason, the people he kills go to his Locker, and the people he capture serve for 10 decades probably at the gunpoint. The miraculous part is that Will does not "merge with fauna, " probably because he does not will to take over the sea. I think there should be an insert on this. Will does not have the Kraken, either. I believe it was Jack Sparrow who killed Davy Jones is the Glitch. So, watch out for the sequels. =p (Remember, that means Jack Sparrow's captain.) I believe Jack and Will were merging souls in The Show when they both Stabbed the heart. Jack does not for sake his duty, so he just is captain of the ship like he wants.