I've been logged into Starhawk pretty much all evening. Servers are a bit on the light side (there are about 1/2 the normal amount of servers active and none are more than about half full), though, so I think the maintenence is not allowing some people to connect.
PSN was scheduled to have maintenance tonight until 8 PM PT, but that has been extended until tomorrow morning. No specific time in the morning has been given for when service will resume.
The maintenance has been extended now until tomorrow morning 2 AM PT....I wouldn't count on it coming back at that time though either, as this is the third update that has been made....none of the updates have been able to get the time correct.