According to Dr. Smith, an MMORPG environment would be a great always-on option to provide training to the troops. Specifically, he says "something like World of Warcraft, but focused on the military training customer." You can even check out his public PDF on work he's already done on this kind of training environment.
The always-on world would provide training scenarios even outside the usual tactical simulation. Your avatars could interact with cultural representations, learning the fine points of behavior while interacting in foreign environments. Want to get your team a dose of decision-making expertise? Set up the environment to run reactions based on criteria you devise. And we definitely know WoW can teach you about a fictional history, maybe Dr. Smith's could help the soldier with some real-world equivalents.
We've all heard about the government exploring virtual worlds before, but we don't often hear that exploration directly connected to WoW. But if 10 million people -- including soldiers -- love us some WoW, maybe there's something in the formula Dr. Smith can use.