For the second time in as many weeks, the PlayStation Network will be down for maintenance from the 2nd February til the morning of the 3rd.
According to the PlayStation EU Blog, following features will be off from 14:00 GMT on Thursday til 8:00 GMT Friday morning: PlayStation Store (PC and Console), customer account management, registration and PlayStation Home.
If you are playing online before PSN goes offline, your multiplayer session will remain unaltered.