Twin prop transports have always been popular, see the DC-2/3/C-47 and many other aircraft including the An-24/26/32.  What is in fact rather interesting is that France and Germany both decided to replace their twin prop C-160 with far larger 4 engine A400M's.  However wonderful the A400M it seems rather clear the requirement for smaller twin engines transports will remain.  Indeed the US program to buy the C-27J was party based on the need for a smaller aircraft able to operate places the C-130 can not but as Congress has pointed out it's significantly cheaper to operate.

If the USAF isn't going to use the C27's they ordered, they should stop the worthless limitation on the US army not being allowed manned fixed wing aircraft, and move all transport aircraft over to that service branch.  The fighter mafia hates anything that isn't fast anyway (another example:  their consistent effort to rid themselves of the A-10 despite its astonishing success as a weapon).@import url http://www.strategypage.com/CuteSoft_Client/CuteEditor/Load.ashx?type=style&file=SyntaxHighlighter.css);" target="_blank">link

2 engines safer?  More fuel efficient I can believe, but for a military aircraft that may get shot at, 4 is safer than 2.