I think you came close to the biggest differentiator: adaptability. Great programmers can dive into a new technology and use their past experience to quickly gain competency in it. If I hand node.js to a great programmer, I expect that he/she will be able to start being productive with it in just a day or two. Lesser programmers struggle to apply their past experience to that new paradigm. It takes months for them to truly get comfortable.
That type of agility is hugely helpful in an organization.
That type of agility is hugely helpful in an organization.