The latest SitRep on the official America's Army website indicates that the US Army is taking their free game to the next level with the inclusion of cooperative play in the next version:

To date, America's Army has been singularly focused upon objective-based, multiplayer gameplay in missions set against a balanced human enemy. With Overmatch, we'll debut two new missions that will pit Rangers and Special Forces against an overwhelming force of Enemy AI Soldiers and Vehicles. Rather than presenting players with the one-to-one odds, as is customary in our current missions, these two new levels represent asymmetric conflict; wherein the enemy outnumbers the U.S. forces by upwards of three-, four- and even five-to-one! The new AI enemy represents a more organized military force than the insurgency/terrorist antagonists of our multiplayer missions.

The SitRep also includes some details about the AI and why they think it is going to be quite impressive.

If you haven't checked out America's Army yet, you should definitely do so. The US Army have put a lot of time and effort into it and have developed a game that rivals many commercial titles. The inclusion of coop will be a great addition to an already impressive feature list.