Well back in the early to late 90's, I remember playing a BBS text game called Legend of the Red Dragon or LoRD to some (without "the" for some reason).  Plus a lot of players who have played the original pen, paper, dice AD&D and D&D (as well as Mekton, Robotech, Mage, Vampires, Rifts, tabletop Warhammer, etc) also play WoW.  I think the majority of WoW players are in their mid 20's to late 30's.  Those who can afford multiple accounts would also be those in their mid 20's to late 30's.

The thing is, what you see online most of the time are 12 to 17 year olds - ones that aren't in university/college yet and those whom aren't in the work force, but I doubt they make up the majority.

LoRD forgot about that one!!!

^_^

And there are others.  I think there was one called Tradewars.  My gosh, I ran my own BBS back then.  Tradewars was so difficult to install for my Iniquity/Renegade BBS system. 

Ah the nostalgia's coming back.  Those were some really great days.