The other two end scenes where far less important then POTC3 to me at least. The scene wasn't just Will coming back for a 10 year visit with his family but (according to the writers and game) was he return to the "real" world where he could stay with his family without having to be Capitan of the Flying Dutchman ever again.
In the movie they said he had to be the captain forever. He gets one day every 10 years to be on land. After that he goes out for another 10 years. Why would Will be released when Davey Jones wasn't?
Actually I felt there would be something to that, was thinking this after watching the movie...a subplot for the next movie of sort. A way to 'cheat' the dutchman rule so they could be a family again-and I'm sure Papa Bootstrap has a play in it. Sure the main focus will be on the fountain of youth but, there will be typical carribeanesque sublots like this I'm sure.
Orlando Bloom has been confirmed NOT to be part of Pirates 4. The story of Will Turner is over. Keira Knightley is still up in the air... but given the "10 years later" ending of Pirates 3, it wouldn't make much sense to include her.