The PlayStation Network service has finally been restored after a lengthy maintenance period which saw several delays.
The maintenance "to upgrade the software" began early Thursday morning and was supposed to be completed the same day. However, for some unknown reason, the maintenance took longer than expected. Sony made several estimates throughout the downtime, but ultimately PSN was back up and running this morning.
Usually PSN maintenance isn't a problem as you can typically continue to enjoy online services without interruption — provided you log in to PSN 5 days prior to the start of maintenance. However, Sony indicated that some authenticated users may have lost access during the maintenance.
All PlayStation owners should now be able to acces the PlayStation Store, apps, and online play.