I also heard WOW is highly addictive and has cost alot of jobs, as in people have enjoyed the game so much that their attendance and punctionality was placed on the bottom of the priority list.
Friends of mine used to always play Runescape, then they all discovered World of Warcraft and switched. But after a couple of months they went back to Runescape. It is not as flashy looking, but the game play is more sophisticated, particularly the trading and quests.