This is all just speculation!
However, I have a feeling some deep conspiricy is involved.
The FBI has been watching SONY, based on there generally poor release and launch of games... This time it was good, and they are supecting some Insider Fraud / Trading type thing.... Enron anyone?
Or...
So Old guy trying to mack on on one of the sony dev's tripped and landing on the power cord to the server room...
Or....
Finally, all of us have been duped, the game was only scheduled to stay live for 72 hours before self distructing! Should've read the find print!
Feel free to post your fanatic reason why the servers are down.