Darth Vader está realmente morto?

Bem, sim. Ele está morto. ele é um fantasma de força no final do ROTJ, e os dois fantasmas da força (Obi-Wan Kenobi e Yoda) que se juntam a ele estão decididamente mortos. Do script (grifo meu)

VADER: (a whisper) Luke, help me take this mask off.

LUKE: But you'll die.

VADER: Nothing can stop that now. Just for once... let me look on you with my own eyes.

Slowly, hesitantly, Luke removes the mask from his father's face. There beneath the scars is an elderly man. His eyes do not focus. But the dying man smiles at the sight before him.

ANAKIN: (very weak) Now...go, my son. Leave me.

LUKE: No. You're coming with me. I can't leave you here. I've got to save you.

ANAKIN: You already have, Luke. You were right about me. Tell your sister...you were right.

LUKE: Father...I won't leave you.

Darth Vader, Anakin Skywalker...Luke's father, dies.

A huge explosion rocks the docking bay. Slowly, Luke rises and, half carrying, half dragging the body of his father, stumbles toward a shuttle.

Luke depois queima o corpo

O livro de Fatos de Star Wars (canon) é explícito sobre o estado de Anakin / Darth após sua luta icônica com Luke. Ele está morto.

With Anakin's death, the last remnant of the Sith is no more, The man who helped destroy the Jedi Order has also ended the Sith, bringing balance to the Force as prophesied years ago.

Anakin's armor is empty - After his death he passes into the Force, as Obi-Wan and Yoda did before him.

A nova (e totalmente canônica) novela júnior da Disney também é bem direta no assunto.

When he looks back down, his father is dead. But Luke keeps his promise. He will not leave his father. He stumbles toward the distant shuttle, staggering under the weight of this giant half-metal man who wrought so much evil.

Leave him there, you want to shout to Luke. He’s the bad guy! The villain! Just leave him and get out of there before the whole Death Star blows up!

Assim como a galeria de eventos oficial do Starwars.com para o retorno do Jedi.

Realizing he cannot be saved, Vader asks Luke to remove his mask so that he may look upon his son with his own eyes. Luke insists that he must save him, but Vader — Anakin — affirms that he already has. Luke's father dies as the Death Star begins to come apart around him. Luke moves toward a shuttle, his only means of escape.

Nós o vemos logo depois como um Fantasma da Força, um estado que é incompatível com a vida.