Interesting debate. Who is the Jedi in ROTJ? Some say luke, but he was never a Jedi until before ROTJ. So how is he returning? Vader on the other hand does return to the Jedi order before he turned on Palpatine and threw him in the pit. Did Luke jump Jedi knight straight to Jedi master or what? I have no dout in my mine that Lucas meant Luke as the Jedi in the title because I'm sure you all know the original name "Revenge of the Jedi" but Lucas changed it because Jedi do not believe in Revenge. So I think the title "Return of the Jedi" would work better if Lucas meant Anakin is returning and not Luke. Let me know if this confuses you.