It's good, but I think for a lot of us, the people that are in to science and space exploration and such, it doesn't really say anything new. It's presented well, and I think it's great as an introduction for kids or people who have never really been interested in science, but not really that great for "us." And as HalfSmokes said, Tyson isn't Sagan. He's great, I love him, but I remember watching the original and getting chills.
In any case, I think it's great to have science based programming on a big network at a prime time slot.