I think he has a good chance down under. He is a very fit player and fit players do good there... but I don't know about his off-season work habits but, if they are good, he should stand a chance.
He will, obviously, be a favorite at Roland Garros. He is one of the best clay-courters around... and that's the only surface Federer isn't god-like on.
He'll probably be my favorite in Roland Garros so, I think he can win a major this year.