Patch Summaries from: WoW Insider (brief) and WatchingWoW.
If the test realm patch notes hold, here are my highlights for this patch:
Shadow of the Necropolis
The day many have feared for years has finally come: the Scourge has launched a direct attack on the lands of Azeroth! Reports of necropolis sightings are coming in from all over the world, the massive structures looming ominously on the horizon, ready to move at Kel'Thuzad's command.