There are some speculations when it was announced that it is Jude Law who will play the young Dumbledore in Fantastic Beasts. He is almost a shoo-in for the role as he is known to have played roles that will show his ability to be a quintessential British man. He is able to show humor while portraying his role without forgetting about the characteristics of the character that he is playing.
The story will tackle how Dumbledore decided to stay positive and stay away from the dark forces which Law will be able to portray so well. I believe that it will not be disappointing to see him play young Dumbledore.