Seems like a topic I have seen a few places today, like over at MMO Melting Pot, is about people playing WoW and feeling as if they are being unproductive. They seem to be missing a point about gaming however that actually goes to show that in a way gaming, in this case playing WoW, is productive.
While I am willing to accept that too much of anything is a bad thing and there is a line, and that line is different for every person, gaming is not as bad a thing as people try to make it out to be.
Everyone needs to have something to stimulate the mind. The mind is like any muscle, it needs to be used or it will deteriorate. That alone makes playing WoW a productive thing in and of itself. It keeps the mind active and in many cases way more active then other common hobbies people choose to pass the time.
If someone watches three hours of prime time television a night, which actually is the number the average person watches, it is considered normal. Even if they watch 5 hours a day when you include some talk shows, or news shows or any other sort of entertainment it is considered fine.
I don't know about you as I can only speak for myself but I find playing a game that requires interaction a lot more mentally stimulating than watching TV.
Many studies have found that people that have hobbies in which they are actively using their mind have better mental health further into life. So exercising your mind playing WoW would indeed be a productive thing. Just like doing some exercise is good for your physical health and eating right is good for your medical health having an active hobby to stimulate your mind is good for your mental health.
Everyone wastes time during the day and most do not consider what they do unproductive. Watching TV, reading a book, going to the bar, going to the gym, fixing up old cars, posting auctions on ebay, etc, these are all things people might do on a daily basis. They are all things people do to relax, to unwind, to have some "my" time with.
How is it that you doing what you want to do with your "my" time is unproductive yet someone else doing what they want with their "my" time is productive?
As long as your hobby (WoW) does not interfere with your normal day to day life and responsibilities you are not being unproductive, you are just stimulating your mental health.