The US Army once considered purchasing a large number of Xbox 360 systems from Microsoft. Computers of equal caliber can cost around $1000 each, but an Xbox 360 starts at only $200 -- quite a considerable cost saving. The consoles could be used as virtual training tools, with games like America's Army and Full Spectrum Warrior placed in army "classrooms" stockpiled with Xbox consoles. The more cynically inclined can imagine the system as an effective tool for recruitment: join the Army, get a free Xbox.
Since they lose money on the Xbox systems themselves, I'm not at all surprise by this move.