When will TES games end ? It's the same thing for WoW : if they wish they can keep on adding content forever.
IMO as with almost every franchise in games and film they'll know when it's too late and won't do a proper ending.
So long as i get a Feat of Strength at the end, I'll be happy...
Who knows how it'll really end, maybe it'll be like Everquest and just, go on and on, or maybe Blizz says "Fuck it, pull the plug!"
I've made the "wow becomes the matrix" joke too many times already. maybe if I did it in a fresh new way.hmmm