Fed is so smart he knew he has not chance against fresher Novak in F ,To play 3 BO5 matches vs top players it can give him only injury but not the title. Fed just made sure Murray's happiness for the win against him to be short, In F Murray felt Fed's fingerprints all over.
Federer knows how hard it is getting for Murray to win his second GS. You start to question yourself will i win other title or i can be next Andy Roddick. It would get harder and harder for him to win again.
Wouldn't surprise me in the slightest. Federer's a smart guy, and facing Nole in the final would be figurative suicide.