I don't care that much either. On net, I think Wikileaks is a good thing, but I've never donated and never would until they are more transparent about their own operations. Re that video, the first half wasn't what disturbed me, but rather the firing of the missiles into the building in the second half.
But there's an obvious strategy for the US to discredit Wikileaks, and that's to find someone - anyone - that appears to have leaked to them, and come down hard on them. Finding an oddball kid suits the story they want to tell, irrelevant of how guilty he may be. But the Wired stuff is just off the wall odd.
I'm working under the assumption that someone named Manning did in fact do something stupid with Wikileaks, which did indeed encourage him to do that stupid thing. That Wikileaks is encouraging stupid people to do stupid things is something that bothers me about Wikileaks; that stupid people are given access sufficient to do stupid and damaging things is something that bothers me about the DoD.