There was a pretty good article in the February 2008 Marine Corps Gazette which investigated why it takes so long to get better equipment to the frontlines. The article is titled "One Single Nail" by LTCOL John E. McLean and, since he is a much more eloquent writer than I, I will quote him:
"The conspicuous lack of resolve in the national industrial base has been discussed repeatedly since the GWOT began. At the same time, however, there appears to be no driving force within the military-industrial complex to foster that resolve or motivate its replacement so as to achieve improvements in equipment design, production, and fielding." He continues, "Likewise, the aircraft industry has become so imbued with long-term, multi-billion dollar programs that, arguably, it has lost the ability to quickly devise, test, produce, and field aviation-related equipment"
