Mufasa: The Lion King (December 20th)
On the origins of monarchy. Do we need a prequel for everything? All that's important is that there was a monarch and then he was killed and we root for his son.
And it's not Hamlet. Hamlet was very much about the moral repercussions of killing. Hamlet was in Claudius' court. Claudius didn't trick Hamlet into running away for the entirety of his youth. The plot of Hamlet was not 'Hamlet kills bad king and bangs Ophelia,' it's 'Hamlet isn't certain that his uncle/stepfather killed his father and his indecision dooms everyone.'
They do have one thing in common though: You don't need a prequel to tell the story of King Hamlet.