Hibbert is talented & offensively his post game is excellent. In fact, I would say he has a better post game than Howard at this point. But it's tough comparing him & Noah. Hibbert is a traditional, back-to-the-basket Center. Noah is a hybrid center (more of a PF playing the Center position). That's not to say Noah doesn't have post moves, because he does but his lower body strength is nowhere near strong enough to compete against bigger players in the post & his touch isn't nearly as soft as Hibberts.
But what Noah excels at, & something Hibbert never will, is his versatility. He can guard every position on the court (1-5). I don't think you can say that about any other center in this league. He also is an icredible passer, as many have stated already, with the ability to put the ball on the floor and lead the break. This to me is what puts him ahead of Hibbert right now. But as I said, they are two completely different types of Centers.