It would teach new crew members the mechanics of the various tasks in a McD's, that's all. At least they'll be a little more prepared when they go "hands-on" in an actual McDonald's. I remember the first time I worked at a McD......training was just; read a book, watch a vid, get to work. It took you quite a while to learn all the sandwiches simply because training was so poorly executed and not every McSandwhich was in the book or the vid. Plus, expecting other crew members to train you is usually flaky at best, and many times, you are "taught" improper techniques in a haste because the store was busy. I would have loved a program like this that would have taught me correctly back then. It would have saved a lot of time and aggravation.
It would make learning the ropes a lot more fun, as well as being more efficient. The end-result would be that customers get more correctly prepared food quicker, and store managers get a more efficient crew. Win-win for everyone. Well.....except for that "fast food is bad for you" thing.
It seems like they could make this a "DS Download Play" sort of option when you are at a McD's. McD's always had free WiFi for the DS anyway. All they would have to do is password protect the program so the average person walking in off the street couldn't access it without the password. The password would obviously be given to the crew and it could spread to the public that way, but they could always make the password changeable at each location. That could work.
I really don't think they'll just release the game to retail though. Most companies like to consider basic things about their operation as "secrets", going retail with a program like this would go against that policy. But these are "money hungry" corporations we're talking about, so who knows....