Ah, I've used a poor choice of words.
Manning indiscriminately 'grabbed' a stack of files and sent them to Wikileaks. He didn't care what he sent, just that he sent something, expecting Wikileaks to sort and withhold the material (which they usually do with the utmost of care). Since Wikileaks ultimately failed to do so, I'd give them the blame, even though there can't be legal action. This rests on my *hope* that Manning didn't intend for it all to be published.
The way I see it, Manning can (and most likely will) be legally prosecuted for accessing and passing unclassified and confidential info to an unauthorized location, but Wikileaks should be scrutinized for their mismanagement of info.
I hope it doesn't lead to the end of Wikileaks, but they really need to set new security standards for themselves. Cablegate could've been prevented.