(The picture I included is of the man who's credited to be playing Bill Turner.)
Bill Turner isn't necessarily still alive (there is a thing called flash backs). Hell, it could even be possible that he has something to do with Jack's blood debt to Davis' Jones. About BIll Turner being cursed, he may not have been. You're never told that he PHYSICALLY took a medallion from the chest, just that he sent one away to Will, so if he didn't physically take one from the chest & was still cursed, then Will should have been a skeleton that night they took him out of the water & Elizabeth after him should have been cursed. But on the other hand, there still is the possibility that he is alive, but then it'd be hard fitting that into the plot....Anyway, I'm just going to wait until I've seen the movie.