I played WoW for a bit (quit last October). Got my character to 70, did the raiding/PvP thing, etc. Overall the experience was 'meh'. I never really played for more than 2 hours a night (3-4 times a week), and it just got too damn boring towards the end.
Wasn't a complete waste though. My girlfriend had to go home for 3 months out of the year, and we played WoW together while she was gone. It was a nice way to keep doing stuff together.
But I digress. I know exactly what Shoe is talking about. My freshman year roommate got hooked, and it was like watching a building fall down in slow motion. Before WoW came out, he played a lot of Counter Strike, but he still went out to parties, went to class, etc. After WoW, he stopped going out with friends, never went to class (he played from 2 PM til 8 AM. Sleep a bit, repeat), and eventually he only left the room twice a day (to shower and run across the street for Subway). Tuesdays (when the servers were down), he'd just sit in front of his computer refreshing the server list (for hours), waiting for his server to come back up.
It was the most pathetic thing I've ever seen.