Its monday morning, because of a leap year error, PS3 fats are having PSN problems and corrupting data. Its best not to turn on your PS3 until its resolved or until Tuesday, or just keep abreast of the situation online.
Apprently its an internal clock issue and associated with a chip, it even stops single player games working. Its best to keep it switched off until 2/3/2010 maybe ?
Slims appear not affected.