Fresh from the news bulletin upon login is an announcement of rolling restarts for a handful of realms this afternoon. At 12:00 noon PDT the realms of Dreadmaul, Caelestrasz, Nagrand, Aman'Thul, Barthilas, Thaurissan, Dath'Remar, Frostmourne, Khaz'horoth, and Jube'Thos will be going down for restarts.
Many people have still continued to experience connectivity issues and major lag since patch 3.0.2 dropped nearly two weeks ago. Instances seem to be a particular problem with people not being able to zone in, getting disconnected upon loading, or generally having issues with mobs and other objects appearing correctly.
I wouldn't be surprised to see more realms added to this list today, and perhaps some extended maintenance (if not an outright patch) this upcoming Tuesday.