The difficulty I have with that article is that I don't know how the jobs in these studies map to engineering or research jobs. I'm thinking of jobs where one has accumulated close to a decade's worth of knowledge before starting.
Related to this, I think it's important to consider that this correlation between g and job performance is conditioned on the fact that the person applied for the job. That sounds trivially true at first, but it means that the applicant felt like they were competent for the job (in the best case; in the worst case, it meant they felt that they had a chance of appearing competent at the job). In other words, what we're saying is, "Of the people who thought they could do the job, the smartest ones tended to do the best."
But if our candidate pool was everyone, I'm skeptical that g would still hold as a good predictor. I think I'm a bright guy, but I'm pretty sure I'd make a terrible nuclear engineer. And with that in mind, we may need to keep the non-g related selection around to prevent such a situation.
