William is now making a comeback through Charles' son and Prince Henry (Harry) will be the first Harry since Henry VIII to hold the title Duke of York (yes, Henry VIII was Duke of York as his elder brother held the Prince of Wales title until his early death.)

So, in that case (Harry as York) what happens to Prince Andrew and Sarah, the curent Duke and Duchess of York?
Hmmmm?

Okay. The Prince of Wales is the title reserved for the male heir to the throne. This is Charles. The Duke of York has nothing to do with the succession line. It is a title afforded to the second of the monarch's sons. If there isn't a second son then the title remains vacant.

When Charles becomes King William doesn't automatically become Prince of Wales and Harry does not become Duke of York. Charles was only given this title when he turned 18 or so. Andrew became Duke of York shortly before his wedding in 1986. It was last used by George VI until 1936 when he became king - a gap of 50 years during which the title was vacant. Andrew will keep this title until he dies. It will then be up to Charles to decide when his two sons will be invested with their individual titles. William could become king without ever becoming Prince of Wales - if his grandmother and father were to die suddenly, but this is highly unlikely. It is also highly likely that, now he is of age, he will become Prince of Wales almost as soon as Charles becomes king.