WoW World of Warcraft Free Trial
Because World of Warcraft will have a monthly fee, most people will want to test the game before they subscribe to it. Therefore World of Warcraft will have a free trial where people can try the game for a limited period of time.
The trial period will probably last for 1-4 weeks, enough time for someone to try the game and decide whether or not it is worth paying for. The trial will probably not have any limits (except for the time limit); it will be just like playing the full version of the game. It is still unsure if a Free Trial period will be available at the time of release.