You know, I never considered this, but come to think of it, you're right. The storyline was based on Shakespeare's The Temptest in much the same way as Apolcalypse Now took its roots from Joseph Konrad's Heart of Darkness.
Who would you cast? No one comes to mind right now, but I think the hardest part to assign would be Dr. Morbius himself. Walter Pidgeon was fabulous in that film, and I don't know who could be cast in his place.
Actually Leslie Nielsen might make a good Dr. Morbius...kind of ironic since Leslie Nielsen played the captain in the original movie!