I play on a very old, very full and very busy server. It's not really surprising that there are queues to get in after a major expansion or content patch. This time around it's been awful, however. 2000 people ahead of me in the queue and an hour wait or more is not uncommon.
What surprises me though is after sitting and staring at the login screen for that long, Deathwing is actually starting to look really cute and adorable.