Newton's success won't be predicated on his God-given talents, of which he has plenty. The biggest obstacle for him will be learning a pro offense. Spread offenses are incredibly simple whe it comes to progressions. Auburn's only has something like 6 to 8 plays that get run out of 15 different formations in order to confuse the defense. It's not going to be that simple in the league.
I don't know what makes people think he's going to fail. He's not Jamarcus Russel. He ran for 1400 yards and had the highest passer rating in BCS school history. Never seen anything like him.
Russell had all the physical ability in the world, and a truly elite arm. Cases like him and VY, though, show that you have to be intelligent and not a lazy a-hole to succeed in the NFL.