True, it's probably little more then a coat of paint on it's house. That being said, they're probably paying more attention to those that just threw eggs all over it, and if they chose, to act accordingly. Not like there woudl be much that would stop them.

It's got a few important uses. Recruiting, public relations, etc. And then, there's the loss of face in having it down.

Even if they don't care that they site id down they will probably care about the public opinion that a couple of script kiddies took down the site if a top US government agency.