An interview with Paul Della Bitta was posted today. Paul heads up Blizzard's eSport team (among other things) and in the interview he discusses WoW as an eSport, the tournament scene and more...

How did WoW become an eSport?

With the introduction of the arena system in the Burning Crusade, we realized with the ladders and the rankings online, we had the basic platform to start running World of Warcraft ladders. So, we decided to start our own tournament this year to see if the community was interested and see how it played out as an eSport.

You can read the whole interview here: Blizzard Interview: Della Bitta.