Sony will bring PlayStation Network down for routine scheduled maintenance tomorrow, November 17.
During the maintenance, users will be unable to access the PS Store, PSN account management and registration services, nor the network from PlayStation.com.
European users will be unable to access these services from 4.00pm until 2.00am, Friday November 18.
US users will be unable to access services from 8.00am until 10.00pm PST.
PS3 owners will still be able to play online during the maintenance and continue to collect in-game Trophies, which will be posted to profiles once PSN is back up.