It doesn't look like a WOW killer. Every now n then I see kids complain in chat about WOW lagging on there computers so majority definitely won't be leaving for this. (Although I still think beefing up gfx will help lengthen it's life..) I don't care for pvp, and just doesn't look appealing anyway.
When I'm done with WOW, I'm done with MMO's altogether though.