UPDATE: BioWare is offering a free day of game time to all players in recompense for the unanticipated server issues:
Thank you for your patience.
Following yesterday's deployment of the 1.2 Game Update, live servers were scheduled for an additional small patch this morning (1.2.0a) to apply minor bug fixes. At approximately 8:30am EST live servers were again brought down, this time unexpectedly, and will apparently remain down until at least 7:00pm EST while BioWare works to address a number of unintended changes:
During last night's maintenance, some areas of the game were reverted to pre-Game Update 1.2 status. Some areas were 'missing' and characters that were in those areas would be unavailable. We took the live servers offline at approx 9:30AM CDT (Austin time).
Our server and deployment teams are now working to rebuild assets for the live servers, but this is unfortunately not a quick process. We currently estimate that our downtime could be up to eight hours, but that time may be extended.
We are expecting the servers to be available again at 6:00PM CDT (April 14th, 12:00AM BST, 1:00AM CEST, 9:00AM AEST). We'll update you with information in this thread when we have it.
We sincerely apologize for the unexpected downtime today. We’ll update you with more details later.
Thank you for your patience while we work to resolve this issue.
The official thread with updates as they're announced can be found on the forums.