Soft skills training, diagnostic medicine and retail are among the growth areas, according to members of the Protocol Braintrust.
I think the thing to look out for are the industries that can benefit from a common UI. If you think of AR as a potential standard UI layer on top of the real world, you could start to imagine massively easier to use systems and massively quicker diagnosis of problems as well as common language for identifying problems.
Today, I would argue that the smartphone is becoming the ubiquitous UI for consumer products. You need an app to set up your home cameras and to get the rental information for your vacation or log your workout. With ubiquitous AR, the UI for all things will be exposed with an AR layer, making virtual control and use of everything from industrial equipment to simple switches in our home to medical diagnosis completely contextual and relevant. Imagine if your vital signs were visible to a doctor viewing you through AR glasses.
Now imagine if he could superimpose your X-rays or brain scans over your own body. Having self-explanatory notes about equipment with very little knowledge about what they are doing will propel industry forward in a way never seen before. These devices and systems will be designed to tell people how to fix them. Ultimately, the hyper-contextual data and information that AR promises will make the UI for the real world less abstract and will appear directly on the world. This will make the use, control, and maintenance of things in our world seamless, easy and scalable and, in turn, will have major impact on labor, training and overall quality of life.