Just so you know, it's regularly scheduled maintenance.
Sony has announced that the PlayStation Network will undergo some maintenance on Thursday, January 15 for about four hours, between 9 a.m. and 1 p.m. PDT.
Sony will be deploying "a series of back-end improvements to the network," which is what they usually say when such maintenance rolls around. The good news is that you might not even notice anything, because if you signed into the PSN before October 8, you'll still be able to play games online and access various apps like Netflix. It's just that the Store, PlayStation Home (which is almost done for good, anyway), and the Account Management option won't be available.
"We thank you for your patience and support and apologize for any inconvenience this may cause."