Rebecca Rubin Senior Film and Media Reporter Disney is welcoming the king of the Pride Lands back to Las Vegas. The studio unveiled a stirring, all-new trailer of “Mufasa: The Lion King” on Thursday at CinemaCon, the annual convention for movie theater owners. “Mufasa: The Lion King” is expected to focus on the early years of the eventual ruler of the animals, as well as his menacing younger brother Scar.