To be fair, I WAS just joking. It's Shaw's ghost.....already decided, ages ago. But if you want MY opinion on the best way to end ROTJ....it would be to have Luke see the ghosts at the funeral pyre instead of at the party. They smile at him, fade away, and then Han & Leia come looking for Luke....no dialogue, the music does the talking, but we clearly see that Luke tells them he has to go, and can't join them at the party, they shake hands/hug....he walks over to his X-Wing and Han & Leia go back to the party and the films ends as it does now.

I think this would have strengthened the idea that the "Returning Jedi" wasn't Luke....but THE JEDI....the order, not the individual....and Luke is off to go make that happen. Unfortunately I think Lucas had had his fill and wanted a nice unambiguous ending.