I remember during the Chuunin exam, when Kakashi was talking to Oro in front of a passed out Sasuke, at first, Kakashi said he would protect Sasuke, even if it killed him. Then, after he thought about it, he said something like, "Yeah, right," suggesting that he would not waste his life protecting Sasuke to defeat Oro. If that's the case, I would have serious doubts to his heart as a Hokage.[/quote]
You're remembering wrong. What he really thought was, "Sacrifice myself to kill him? Am I crazy?" after seeing a horrific vision of his own death -- meaning that Orochimaru was so far above him he would waste his life and still not be able to touch him.