Update: After a very lengthy outage that left users around the world unable to play any of their games, the PlayStation Network is now back up and running once again this morning.
While details are scarce as to what happened so far, the Ask PlayStation Japanese X account offered up an apology. "This problem has now been resolved. We apologize to our customers for any inconvenience caused."
Original Story: Nothing worse than getting some down time to game only to boot up your PlayStation and be unable to play anything.
Unfortunately that is currently the case right now with PlayStation Network currently experiencing issues. The issues started about 2 hours ago as of this writing and are still continuing. There is currently no time table for when it may come back up. You can check the status updates here.

Interestingly many different networks are having issues as earlier today Verizon suffered a serious outage that caused disruptions to its service. It has since been fixed and the FCC is investigating why it went down.
We will keep you updated if we find out any new info.