The game's producer has implied that there might be delays on the horizon if the outage goes on for too much longer.
From Software has admitted that Sony's ongoing issues with the PlayStation Network have proven slightly problematic for the development of Dark Souls, the spiritual successor to its notoriously hard action RPG, Demon's Souls.
While he didn't go into details, producer Kei Horono implied that the PSN situation was hampering development so much that there was a question mark over whether the game would make its October release date. Horono downplayed this possibility a little though, saying that From Software was in contact with Sony and hadn't altered its plans.
It's not hard to see why the PSN problems are having such a negative effect: Dark Soul's has the same punishing gameplay as Demon's Souls but has a much more robust online component. With this in mind, not having PSN available for several weeks must be playing havoc with From's development schedule. Sony has recently said that its network could be working again in a few days, so hopefully From will be able to get back to work properly soon.
Dark Souls is theoretically coming out for PS3 and Xbox 360 on October 11th.