The Playstation Network will be down today, August 30th, for maintenance until 12:30 PM Pacific Standard Time. Players trying to sign in could possibly encounter difficulties, as well as there will be no buying, downloading, or managing accounts preferences on the Network.
The PS Twitter feed will update as soon as the maintenance is done, so we just have to sit tight until then.
You can still play games and whatnot, the Network is the only thing affected. So just keep this in mind.