PSN down, will Sony prevail?

As some of you may already know Sony's Playstation Network has been down since last Wednesday. Sony announced on it's blog that "An external intrusion on our system has affected our PlayStation Network and Qriocity services." There have been all kind of rumours around this news. First and maybe the biggest rumour being that it was the work of the almighty Anonymous, but I think that by now they can be left out. They have also stated that they didn't do it. Some other minor rumours claim that Admin Dev accounts were breached and that a custom firmware which allows the use of fake credit card info was released. The real reason might be some combination or it might be something totally else.