We sorta figured this was coming but it's still annoying.
Sony has been battling to keep the PlayStation Network alive and kicking throughout Christmas Day and currently, as per the PlayStation Support site , the service is down.
They've been aware of the ongoing issues over the past 24 hours or so and they continue to work on those problems. But it's not like Microsoft can gloat; Xbox Live has had trouble with the video and music store and other reported issues have surfaced as well. Looks like the tech powers that be want to cause problems this holiday season but really, who cares? Can't get online on Christmas Day? Gee, that's tough. There has to be something else you'd like to do.
Anyway, keep checking with Sony for updates on the PSN.