Let's get a bit Dr Phil and suggest that the one thing World of Warcraft does better than any other game is instil a sense of ownership and belonging in the player; an urge to set themselves ahead of their playing peers.
You will get more play out of this than titles almost double the price; Terrific incentive to dust off your WoW discs.
If you weren't a fan before; this wont change your mind; Blood Elf Paladins (just kidding; How about a new class; Blizzard