I am not sure if I am the only one who experienced this or not but I went afk today for over 2 hours while leaving wow on and when I came back, it was still online and logged in as usual instead of returning me to main character selection screen and usually after so long, disconnected from server message and main login screen.
It's hard to check because we, in EU at least, get disconnected often and randomly since launch but if you don't, try to confirm if this is indeed true.
Helps a lot with camping things :P