Yoda had Insight Too!
I was watching ROTJ the other day, and i realized something for the first time, maybe everyone else already knew, but i hadn't made the connection.
Yoda knew Luke was going to turn his father back to the light. He told Luke "One thing remains, you must confront Vader"
Now in confronting, (and then turning ) Vader, Luke solves his other major problem, Palpatine. If Luke had killed Vader, he would still have had to deal with the Empourer who obviously outclassed him.
If Yoda had intended Luke to kill Vader, he would have said, you must confront vader, and then confront palpatine, but Yoda knew Vader would turn and then destroy Palps.
This gives much credibility to the argument that Yoda spent his time on dagaboh becoming much more powerful then he ever had been. He was unable to forsee anything concerning Sidious during the clone wars, but by the time of his death, he could see it all laid out before him, and it all happened "just as he had forseen"
I think he developed the power of foresight b/c he saw how useful it was to Sidious. Whaddya think?