It's generally accepted that it's a good idea to avoid cocaine unless you're really sure that you can take it without getting addicted. Similarly, I think it should be generally accepted that it's a good idea to avoid WoW unless you're really sure you can play it without getting addicted.

I had a friend who literally forgot to go to work for two days because he was so busy preparing for a soccer match. Or I'm sure we all know a guy/gal who was/is drinking all too much.

My point is, you can take any hobby too far, it doesn't matter what it is. The interesting thing is, no one blames soccer or alcohol (most of the time it is some deeper issue thats the problem, not alcohol), but everyone is blaming WoW. The problem isn't WoW, the problem is the person who can't treat it as a hobby.