Yea, you can't play anything online without the Network. So let me just straighten everything out so you guys actually know what REALLY happened so we don't get any more false and/or incomplete reports from a particular someone on this thread.
1) System was hacked by a single member of Anonymous on the 17th, which resulted in siphoning personal information from a number of members.
2) The hacking continued on for 2 days, into the 19th.
3) By the night of the 20th, Sony realized they couldn't put a stop to it, so they shut down the Network that night, posting a blog to say it was an "unexpected occurance".
4) Because only a single member did the hacking, Anonymous denied any involvement with the PSN hacking when all fingers pointed at them.
5) 1 day later, the single member who hacked the Network told the others it was him, therefore Anonymous re-posted that day, admitting they were responsible. It is also the same day that Sony finally disclosed that the system was hacked.
6) By day 3, the 23rd, Sony was finally able to regain proper control of the network and began the real maintenance (resulting in the error messages turning into "Playstation Network is undergoing maintenance").
7) May 24th, police investigation is now hitting full swing.
8) May 26th, full diagnostics has confirmed a good percentage of members' personal information has been stolen and that, thank god, credit information of any kind was not even touched and that the full encryption/firewall/protection server were completely untouched.
9) May 27th, server rebuild and reinforcing starts, and PSN will go back online in roughly 7 days, or whenever Sony feels that the servers will be fully protected and that an incident like this will never happen again.