I don't think he's any better of a passer than Tim Tebow... And while he's got plenty of 2nd gear speed while running downhill, I don't think he has quite the type of quickness that will translate to the NFL, or the throwing ability to get him by.
Face it... The NFL is still a league built for elite pocket passers who have a quick first gear and can think extremely fast.
So far it seems like Newton's best plays go "read, read, truck this poor fool in front of me for 8 yards." He won't be able to do that in the League.