Is poker skill just intelligence?

Just read an article from card player magazine:
article

I thought the question was interesting and was wondering what others opinions might be. Do you think some people are naturally more inclined to play poker better than others? Has anyone hit a wall in terms of their learning?

I consider myself fairly intelligent, so I was able to learn the basics at a fairly quick pace, but I think my learning has hit a plateau as of late. Now that I'm focusing on more specific skills like betting in certain scenarios, as well as more of the intangibles associated with reading people, I've found that my learning has slowed. I find the psychology behind poker, and all things in general, interesting, so I don't mind spending more time. I would however, like to find something to bring my game up another notch.

So, anyone else have any ideas/opinions on this subject?