For some time earlier this year, the WikiLeaks site had been off-the-air while they sought additional operating funding and the release of the Collateral Murder material was amongst the first items they'd publish in 2010.
Since that time, there have been rumours circulating of a cache of 260,000 diplomatic cables that Manning also provided to WikiLeaks, a fact denied by founder Julian Assange, although whether his denials hinge on the fact that there were 259,999 instead of 260,000 (for instance) remains to be seen.
Yesterday's release of approximately 90,000 militarily-derived messages, dubbed The Afghan War Diary 2004 - 2010 paints a very different picture of the progress of the conflict that the authorities would liked us to have believed and will dramatically raise the level of tension between US authorities and Assange.
It has not yet been determined whether these 90,000 messages are part of Manning's 260,000; perhaps we will never know, although Assange has said many times that the WikiLeaks site has regularly been receiving far more leaked information that could practically be published on the site.
Julian Assange, defended publication of the material in the face of US anger; "If journalism is good, it is controversial by its nature."