Since the file would be useless without the pass key, that alone did not release the cables but it did assure that should something drastic happen, say Julian should meet with a mysterious accident, by simply releasing the key, the cables could be made public.
I'll let Bernice Keane take it from there:
The problem was, the password was made available, by none other than The Guardians David Leigh, in his book released in February this year co-written with Luke Harding, WikiLeaks: Inside Julian Assanges War on Secrecy. An extract from the book, which was published after the encrypted material had gone online:
Eventually, Assange capitulated. Late at night, after a two-hour debate, he started the process on one of his little netbooks that would enable Leigh to download the entire tranche of cables. The Guardian journalist had to set up the PGP encryption system on his laptop at home across the other side of London. Then he could feed in a password. Assange wrote down on a scrap of paper:
Thats the password, he said. But you have to add one extra word when you type it in. You have to put in the word Diplomatic before the word History Can you remember that? I can remember that. Leigh set off home, and successfully installed the PGP software.
Leigh thus, as part of his effort to cash in on his once-intense but by then-soured relationship with Assange, had revealed the key to decrypting the entire set of cables that had been available online.
The book was published last February but it took a while for someone to put one and two together and make three. When they did the cat was out of the bang.
The Guardian for it's part claims they had been told that the pass phase would expire and be deleted. The Guardian's solution was for WikiLeaks to "remove the files" that they had put up for download. Somebody needs to keep them away from computers. They simply don't understand these things.
For WikiLeaks, it then became a question of attempting to control this process or not. They decided to get ahead of the imminent hostile or uncontrolled release and attempt to control it.
This accounts for the sudden release of over 100,000 cables in recent weeks and the setting up of #wlfind and the final release of the full quarter million unredacted cables yesterday.
Shortly before deadline, Wikileaks was conducting a global consultation to determine if it should release the unredacted cables itself, with nearly all opinion favouring release.
I'll leave the parsing of blame to the comment section. I've read WikiLeaks Exposes Thousands Of Informants and heard a lot of confusing news reports. So I thought you deserved a simple telling of what happened.
From there you'll have to make up your own mind.