Looks like a whole lot of people, including me, are having this problem today. You can always tell its not just you when you go to the forums and see like 5 threads at the top all saying something about the PSN (or SEN rather) not connecting. I hope it gets back up soon and we find out whats going on.
same problem here!! now is 3-29 ans i dont see any updates or new about fix this, i know you can fix it just powercycle the ps3 but that is annoying specially is u playing online anyone know what is going on