Straws in the wind maybe but last week the well known physicist Steven Hawking added to the debate claiming that AI (artificial intelligence) may be the last thing that humans design. See here: http://www.independent.co.uk/news/science/stephen-hawking-transcendence-looks-at-the-implications-of-artificial-intelligence--but-are-we-taking-ai-seriously-enough-9313474.html
Hawking's point and that of Frey and Osborne is that the changes that we are now seeing - self driving cars, Siri, Bing, self service tills and so on -- are all happening at an expanding rate with no one in overall control. Before we blink our world will have changed dramatically. A computer programme that can read 570,000 pages of legal argument and debate in 48 hours and summarise potential defence positions is already having an impact on legal research. Meanwhile another programme helps doctors diagnose cancer using information from 1.5 million patients and 4.5 million pages of medical text. How can people compete? What will they do?
The answer according to Frey and Osborne is that there are only two areas you can be confident of that humans will excel in: creativity and activities that demand persuasive skills. This is because computers are not so good in these areas.
The implications of all of this silent revolution is that schools need to change in fundamental ways to exploit and develop students' skills in these areas. And this is where the relevance of PBL comes in again. But how many teachers are talking to their students about an emergent world of machine intelligence that is going to look very different? Another PBL topic perhaps...