McGonigal makes some good points in this short video, especially about how dealing with things in a video-game environment — like failure, or social interactions — can be greatly helpful when one eventually has to deal with them in the real world. She also helped put together Urgent Evoke, a large-scale multiperson game where you collect achievements by performing world-saving tasks.
The kids these days, they love their gaming. So it makes sense to ask how that passion can be put to good use. Personally I’m fascinated by the prospects of using games to teach people science. Not just facts and features of the real world — although those are important — but the scientific method of hypothesis-testing and experiment. Games already feature exactly those features, of course; everyone who figures out the “laws of nature” in the game world is secretly doing science. It wouldn’t be that hard to tweak things here and there so that the techniques they were practicing connected more directly with science in the non-virtual reality.