The new patch released for World of Warcraft, 3.0.8, seems to be causing realm-wide crashes when Wintergrasp changes hands. This problem has been remedied by disabling it entirely by simply hard-coding the faction in-command of Wintergrasp. This will be fixed quickly, we are told. For the time being, we must all be patient and wait for the coders to fix these minor issues. With these fixes, the servers should be more stable. There were rolling restarts on all realms from 5 AM to 6 AM. Additionally, there are some documented issues as well that should get attention soon. All-in-all, it was a pretty solid patch day from Blizzard.

Source: World of Warcraft Forums