Some progress is being made in the effort to bring Playstation Network back online. Currently, at this time an update is available for download which will assumingly address issues discovered from the hacker attack almost two weeks ago.
Although this update is available, if you attempt to sign into PSN, you will still get an error message stating maintenance is on going.
If anything, this means we should see online capabilities back within a matter of days, if not sooner.
UPDATE: To view if service is back up in your area, click here.