The American defense etablishment may be huge and not prone to change, but the Pentagon seems to have been surprisingly nifty on this account. Or rather: those who have propagated this change seem to have had a fair amount of influence within the Army (as the QDR showed, there seems to be no support for or plans about major realignments of budget, meaning that the well-intended reforms for preparing for and executing the Long War proposed with the QDR are not funded on any meaningful level when compared with e.g. the missile defense bills). Thomas P. M. Barnett who more or less predicted all of this change ought to wake up feeling good about himself every day.
The change from army battles to effects based COIN is a huge and very difficult step for any military organization. The lesser NATO members have to some extent already been through this reorganization during the 1990s when their Departments of Defense were looking for a functional raison d'etre (in terms of both funding and strategy). But the challenge is bigger for the US Army exactly because of its prowess in the military arts: the ingrained self-understanding of the soldier (legitimate and non-reflexive use of power; friend vs. foe dichotomies; imposition of strategic will on opponent) must necessarily clash with a political conceptualization of counterinsurgency, which demands a much more holistic or contextual understanding of the processes related to the "enemy" -- because here "victory" equals not his "defeat" but his succesful integration into a democratic, non-violent political process (minus those who cannot accept the new setup).
This change is nothing less than a de- and reconstruction of the military ethos -- at strategic and tactical levels: the politics of the mission is everywhere; everything is communication of intent -- and so collateral damage becomes heavily fined. Interestingly, the US military's realignment to politically sensitive counterinsurgency is functionally akin to the civilian humanitarian agenda's call for the use of the military instrument sparingly and surgically. Actually, the "contract" between governments and people in the Western, pro-UN circuit of countries about the use of force as an element in humanitarianism relies on this precision of means and similiarity of goals (basically fusion) with development policy.
The New York Times has a fine piece about this whole reorganization in practice: "Mock Iraqi Villages in Mojave Prepare Troops for Battle", which of course is neither straightforward to train and learn, nor easily implemented in practice beacuse of the (here: domestic) strategic context:
UPDATE: Washington Post has an interesting article on the situation in Iraq - quoting some of the stabilization & reconstruction savviest people, including Dobbins, Hammes and Wilson III: "Merits of Partitioning Iraq or Allowing Civil War Weighed".
The troops who come here are at the heart of a vast shift in American war-fighting strategy, a multibillion-dollar effort to remodel the Army on the fly. Here, the Army is relearning how to fight, shifting from its historic emphasis on big army-to-army battles to the more subtle tactics of defeating a guerrilla insurgency. The changes in the Army's emphasis are among the most far-reaching since World War II, all being carried out at top speed, while the Iraqi insurgency continues undiminished and political support for the war ebbs at home. American commanders say publicly that they still believe they can win the war, especially now with a more coherent strategy to combat the insurgency and train their soldiers to fight it. (...)
For the first time in more than 20 years, military planners are revising the Army's counterinsurgency manual, adding emphasis on nation-building and peacekeeping — subjects once belittled by the Bush administration. At the Army's Command and General Staff College in Fort Leavenworth, Kan., officers are being required for the first time to complete a course in counterinsurgency. (...) Junior officers are being encouraged to take greater initiative to adjust to local circumstances. An old military tradition of chronicling the lessons learned on the front and passing them on to other units has found a vital new outlet in password-protected Internet sites where platoon commanders and more senior officers can exchange combat experiences. (...) One third of the American troops now stationed in Iraq have been through the course here, and entire brigades — each with 4,000 soldiers, sometimes more — are processed through here every month. But it is still unclear how much effect the new training is having in the field.Indeed, even as the new training strategy moves forward, American units are substantially withdrawing from Iraq's streets. With the country sliding closer to civil war, Iraqi military units, many of them of uncertain quality, are now taking the leading combat role in nearly half of Iraq's territory. (...) "There is a paradox in the approach," said Kalev Sepp, a former Special Forces officer and one of the most vocal proponents for changing the Army. "The training in the United States and in Iraq is teaching all the right things — decentralization of authority and responsibility to the lowest levels, engagement with the Iraqi population, cultural awareness and political sensitivity — the full broad range of measures needed to defeat the insurgency." "But on the ground," Mr. Sepp said in an interview, "the troops are being moved onto these large consolidated bases and being drawn away from the population just at point that they have been trained to engage them."
Later UPDATE: On the ground in Afghanistan the US Army knows how to counterinsurgency; see this WashPost article: "US Commander in Afghanistan Thinks Locally".