Im getting my ten cents in this one. Yoda and Obi both needed to wait for the perfect time to train Luke and Leia but the events from Eps 4 prevented Obi wan when he allowed himself to die to help luke and the others escape. so it fell on yoda to pick up where Obi Wan left off. but we all know where the events went after that. but yea i have to admit Yoda knew who Starkiller was but never did anything about it allowed him into the cave with no effort on a fight or anything. Also from what ive gather Sith can mislead people to beleiving they are something when they are not. Starkiller from the game was not a clone if everyone has forgotten from the events of the first game when Vader stabed Starkiller in the back and then came back on a meddical bed because of vader brought him back from the dead then. Unless you do the Dark Side ending in Force Unleashed 2 you would still think Starkiller was a clone but he really wasnt he could of been thrown to the brink of death at the end of Force Unleashed 1 but that is the Question everyone is wondering, i have gathered this much from putting things together.
Stormtroopers fear me!!!!