According to the Network Status Page:

Downtime scheduled - Downtime scheduled 06/17/2008 - 7:00 AM Pacific Daylight Time

This is a notification that US worlds will be updated at 7:00 AM Pacific Daylight Time on 06/17/2008. The estimated downtime will be 1 hour.

Downtime scheduled - Downtime scheduled 06/18/2008 5:00 AM London Time / 06/17/2008 9:00 PM Pacific Standard Time

This is a notification that UK worlds will be updated at 5:00 AM London Time on the 06/18/2008. The estimated downtime will be 2 hours. 

SOE Operations team

While you're jonsin' for EQ2, check out our preview of the the next world event, Void Storms: The Invasion!