From the sounds of it, the PSN is down worldwide. Sony did not warn anyone about maintenance, but I have read they shut the servers down for "emergency maintenance", in other words, they're getting DDoS'd and refuse to admit it.
We can thank the hacker group know as "Anonymous". As that is not known right now, to have a world wide shutdown only screams hacker. You can check out my blog about "Anonymous" here. So until further notice, might as well blow off your Wii or just play a better system, the XBOX 360. :D
Sony said Thursday that its PlayStation Network, the online service that connects Sony's game consoles like the PlayStation 3, may be out for a "full day or two" due to an unexpected and unexplained outage.