I think they should go for an off the wall concept with it...
Rambo, having been indoctrinated into the Mujahadeen way of life, following his time spent fighting alongside them versus the Russians, is now a fully-fledged Islamic fundamentalist.
I can see the trailer now (Engage movie trailer deep voice) This summer, one man, and only one man, is going to make a difference. He's taking out the trash in downtown Guantanamo. To rescue his Muja buddies that everyone else left behind... Cue Stallone soundbite: 'Allahu Ahkbar Muthaf*ck*r' Cue Rotor Blade noise... Fade out. Rambo 7, Rated R.

Chock