Anonymous need to read some books on strategy, because this just doesn't make any sense: what are they trying to accomplish? With their previous targets like HBGary, at least you could say that they were taking down corrupt and/or incompetent contractors, but this is different. Booz Allen is a much bigger organization, not some fly-by-night that can easily be folded up. Furthermore, while this does demonstrate that their security had serious problems, it does not demonstrate the kind of gross malfeasance that could actually take a company down.

As for the U.S. military, this is certainly going to cause the U.S. military some inconvenience, but not any serious long-term harm. What will happen as a result of this is that federal law enforcement will now start going after Anonymous in a way that they have not previously done: federal felonies have been committed, and further such crimes are highly likely. Serious resources are going to be devoted to tracking down the responsible parties. Anonymous have developed a false sense of security because nobody has yet gone after them with the full resources of the federal government, and because their interactions have largely been limited to exceptionally inept contractors. While there are plenty of incompetents working for the government, there are also lots of people who are very talented and capable, and Anonymous is now going to find themselves dealing with the latter category.

In summary, they have not done any lasting damage to the government, but they have turned themselves into priority targets. I don't see the upside for them.