My understanding is that the strongest predictors of success that psychologists know about are:
1. Intelligence 2. Conscientiousness [1]
It's also my understanding that these factors usually are correlated under 40% as success predictors. Seems that a lot of it is just plain luck and/or environment. I don't see raw intelligence not being important towards success anytime soon but I don't doubt how as access to information/technology increases, that other factors will begin to dominate as differentiating factors.