Hmph. Wow (no pun intended): a thread that I can speak to both as a player and as a person who got a {relatively useless} degree in psychology.
You have to consider the nature of the (cough) drug, or if it is less offensive to your sensibilities, the medium of addiction-- lolzorssrryImaLargenottamedium.
Is World of Warcraft physically addicting? To crib from Yahtzee, Short answer, No. Long answer: Nooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo.
This is not a subject that is open to debate. As much as WoW might create some sort of unique crescendo of neurological soup within a person's brain, the mechanism by which it does it is not a physical one. I.e.- to be physically addicting, the mechanism of addiction must involve adding an external chemical to the mix.
Is WoW psychologically addicting? Sure. But people, I hate to break it to you, there are people out there who are psychologically addicted to TEDDY BEARS. (I am not even fucking kidding.) You can get psychologically addicted to your SOCKS if you are that particular brand of messed up, ffs.
The long and the short of it is that there are people who will get addicted to something, because, frankly, they are on some subconscious level looking to invest that amount of attention and obsession into something. WoW, because it is very very popular, just offers the convenience of opportunity.
Next subject.