BioWare announced an unscheduled maintenance on the official forums today.
Community News posted:
We will be performing an unscheduled maintenance this Thursday, July 26th, 2012. After the maintenance, there will not be a new patch to download.
The servers and SWTOR.com will be down for four hours on Thursday, July 26th, 2012 from 2AM CDT (12AM PDT/3AM EDT/8AM BST/9AM CEST/5PM AEST) until 6AM CDT (4AM PDT/7AM EDT/12PM BST/1PM CEST/9PM AEST). All game servers will be offline during this period. This maintenance is expected to take no more than four hours, but could be extended.