As you can see with all these threads the OCE servers are screwed, there is huge lag in area’s that creates a 1 to 2 second delay for instant spells and worse when looting, Instances are experiencing long load screens, and in some cases (mists), it may not even let you in at all, after a few minutes you either disconnect or zone into, if you don’t get into the instance you end up at Oribos (I assume because you got kicked from the dungeon).
Of course if you close wow you then get the Character is already logged in “A character with that name already exists” error which can take up to another 30 minutes to clear.
There is constant disconnects which follow no pattern, different toons on different accounts, my bank alt who has no addons get disconnected surfing the AH for instance, after reconnecting from a disconnect, world quests you have completed show back up as if you never completed them and you end up in different places to where you disconnected, almost like a rollback, but the reward is still in your bags.
Anything I have forgotten add it in here be good that there is a list!