I've always wanted to see the Luke/Obi conversation cut completely. It's pure exposition, and I think it's a little too convenient that Obi can pop up any minute and have a long talk, it cheapens his death. His appearances should be mysterious and brief. I think Dagobah should end after Yoda dies in the hut with his last words "there is another skywalker" the fact that you know who ten seconds later ruins the tension. Luke should discover that on his own and it should be revealed to the audience in his conversation with Leia.