I am currently playing GW1, Star Trek Online and WoW. I don't give a flying broccoli whether one kills the other or not. I don't give my left almond nut on my desk whether or not GW2 "dethrones" WoW or not.
I STILL PLAY WARCRAFT 2
I STILL PLAY TIBERIAN SUN
I STILL PLAY LEGACY OF KAIN
Do I stop playing them because Warcraft 3, Tiberium Wars and Darksiders come out? NO. I LOVE ALL THESE GAMES.
So WHY does the discussion when someone mentions an MMO always instantly veer to: "It will kill WoW/won't kill WoW". WHO CARES?