Kiss your Call of Duty goodbye tomorrow, Thursday November, 17th, as Playstation Network goes down for maintenance. According to the Playstation Blog, you will not be able to terrorize other players in Demon's Souls from about 8AM to 10PM, a 14 hour period while Sony tinkers, though it is unclear what the nature of the tinkering is but it is said the network will be down for "routine scheduled maintenance."
Sony's Patrick Seybold has said however that some of the account management and registration options will remain live and for the lucky few, some online gameplay might work but it is on a completely random basis.
Playstation owners, as unfortunate as Sony's choice to go down for 14 hours during peak time is, you dealt with a 23-day exile earlier in the year, this should be nothing!
My official suggestion: Download yesterday's release, Jurassic Park: The Game on the Playstation Store at 7 AM and have yourself a Tyrannosaurus Thursday.