The original tiltrotor vertical takeoff aircraft was canceled during President George H.W. Bush's presidency by then Secretary of Defense Dick Cheney. It was a problem child that ran up against the technological limitations of the day. Now, almost twenty years later the MV-22, "has had the lowest class A mishap rate of any rotorcraft in the Marine Corps during the past decade", according to the Naval Safety Center.
The Osprey was written just a few years ago as too expensive, too dangerous and just unworkable, but now is the cutting edge in tactical airlift capabilities. After several years of deployments in Afghanistan and Iraq you would probably be hard pressed to find a military unit that would not want more of them. They will have to wait because as of April 2010 there were only about a dozen deployed with plans for fifty by 2016. This seems like a ridiculously small number given the Pentagon's own admission in the last Quadrennial Defense Review that the military was in serious need of more rotor craft.
More ground combat units supported by more helicopters and tiltrotors seems to be the way to go, but the trend toward smaller and smaller ground forces is moving forward. This means more and more reliance in missiles and air power which makes sense against a conventional power like China, but for at least the near future we will continue to fight tribal gangs with AK-47s and RPGs. The Osprey can add to ground units' tactical superiority against all enemies, current and future.