http://kitup.military.com/2011/01/in...olt-cm901.html
I think Colt may be throwing a piston gun into the improved carbine program. They have a lower that can change between 5.56x45 to 7.62x51. Ambi controls, and that kind of modularity would be interesting. It is all in the video. It is all speculation, but the timing is pretty interesting.
Still don't see the Army moving to completely different weapons system, so the new Colt makes sense. Unless someone develops a caseless ammo that is affordable and can be fired by electronic impulses instead of mechanically we will continue using this system. It may be an 50 year old system but it works and we are conitnuing to squeeze more and more potential out of it. Plus the Army is asking for funds for an order of 19,406 new M4A1s in 2012.