Guys, don't worry, the PlayStation Network will be offline almost all day tomorrow but it's just for standard routine scheduled maintenance. It will be down from approximately 8am until 10pm PST. During the maintenance you won't be able to access the PlayStation Store via your PS3 and PSP, your PlayStation Network Account Management, or PlayStation Network Account Registration.
You also won't be able to sign in to the PSN from us.playstation.com, so don't try to! However, if you still want to play games and get trophies you'll be able to. Your profile will be updated once the PSN is back up and running.
In other words, keep slaying dragons in Skyrim and streaking your way through Saints Row. The PSN will be back up before you know it.
Source: PlayStation Blog