Luke: No, of course not.
Yoda: Yes I do. Yes I do. Sick have I become. Old and weak. When 900 years old you reach, look as good you will not, hmm? Soon will I rest, yes. Forever sleep. Earned it I have.
Luke: Master Yoda, you can't die.
Yoda: Strong am I with the Force, but not that strong. Twilight is upon me, and soon night must fall. That is the way of things.
Luke: But I need your help. I've come back to finish the training.
Yoda: No more training you require. Already know that which you need.
Luke: Then I am a Jedi.
Yoda: Oh, heh-heh-cough. Not yet. One thing remains. Vader. You must confront Vader. Then, only then, a Jedi will you be.
Luke: Master Yoda, is Darth Vader my father?
Yoda: Hmm, rest I need. Yes...
Luke: Yoda, I must know.
Yoda: Your father he is. Told you, did he?
Luke: Yes.
Yoda: Unexpected this is. And unfortunate.
Luke: Unfortunate that I know the truth.
Yoda: No. Unfortunate that you rushed to face him. That incomplete was your training. That not ready for the burden you were.
Luke: Sorry.
(Whew. That's all I have right now. I'm afraid I'll get Yoda's death words mixed up, so I'll let someone else do the honors. I'll nail Obi-Wan and Mon Mothma's lines later on...)