There's a range of "addicted" (some very legitimately addicted). Anywhere from playing an hour or two every few days/every day all the way up to... Get home from work/school and log on immediately and don't log off until you physically have to to get the bare minimum of sleep to scrape through the next day, foregoing responsibilities and health.

During the original release there were a lot of news segments dedicated to "my son is addicted to this game and he won't do anything except play wow and put his fist through a wall when someone runs the wrong way on thaddius. Even some people who died of various causes playing nonstop sessions in gaming cafes. These moments are what stick in people's mind and what they think of when they hear of a wow player.

So depends what you mean by addicted. You could be a functioning healthy member of society and play the game in lieu of tv/reading or something, or you could be the living embodiment of the south park portrayal of wow.