I think the amazing thing with the Niners is how Alex Smith has finally started to click. I always defended Smith, because he's had so many OCs and so much overturn over his career. But it was getting harder and harder for me to argue that he "just needed the right coach." Until now, that is. Harbaugh has found something in him and turned him into a really good centerpiece for the 49ers. Everyone talks about their defense, but honestly they're a very balanced team, and that offense can move the ball.
As a Saints fan, I was disappointed they beat the Steelers, but I can't deny their talent. If the Saints have to go into Candlestick to beat them, it isn't something I would love (although I do think the Saints can beat them if they get a quick start and force SF to abandon the run).