Previously set to drop in 2012, G.I. Joe: Retaliation is now due out March 2013, with the studios prepping a 3D release... and here's the new trailer.
In it, we see that the G.I. Joes are not only battle their mortal enemy in Cobra, but are also forced to go up against the U.S. government, with an impostor at the helm who allows Cobra to take control. So, there's no one trust but themselves. acting on their own.
G.I. Joe: Retaliation will open, at last, on March 29th, 2013.