Thunder Run is a powered family coaster that goes in and around the park's iconic Wonder Mountain, so the test is starting out on a smaller ride.
According to the report, visitors can check in at the Thunder Run Virtual Reality booth seen above, where guest must sign a waiver and agree to participate in a questionnaire about the experience. They're given an access card to enter the line, at which time they get to ride.
From the photo, the virtual reality system looks like it is in the form of goggles that riders wear, which allow them to enter the virtual world. The report suggests the goggles are synced with the ride's motion and give a fun experience - though no word yet on the content of the virtual world.
Now that we have seen how the "virtual reality on a coaster" plays out, I have to wonder if the chain would make this a pay-extra experience at the parks. I would think it could put a lot of stress on ride capacity if employed to all visitors. Looking forward to hear more reviews of the test as they come in!