Looking at VSP06's log, the server was down between 7:45 PM PDT, Saturday 30 August and 3:10 PM PDT, Sunday 31 August. If your an East Coast Aussie like myself, then the times translate to 12:45 PM AEST, Sunday 31 August to 8:10 AM AEST, Monday 1st September.
So for approximatley 19 & 1/2 hours, the server was out of action, and it meant that if you had one of the above mentioned work units to return, you would've had to have waited for the server to start up again. Nobody should have had any problems receiving new work units however, as your PS3 would still have 3 different servers to download a work unit from.
PDT = Pacific Daylight Time = GMT-7
AEST = Australian Eastern Standard Time = GMT+10