I would have to agree with this statement. Wow is not dying, nor is it making much growth currently and that is for one simple reason. The game is almost 7 years old, how fresh do you think they can keep it? I personally think that MoP is a phenomenal step towards tweaking the game in a newer direction that hasn't been done before in wow (speaking in terms of the asian theme) as well as all the different little things to do. Who cares if the game drops a few million subs? It is still the largest MMO ever made and to be honest I don't see it being dethroned anytime soon. I know somebody is going to quote me and give me the "LOLOLOLOL SWTOR WILL R4P3 UR FACE LOLOLOL" But honestly I don't care. I have heard the same arguement multiple times, no other MMO has ever gotten the job done and I doubt even a Star Wars game will get the job done. Maybe it will, but I am going to call this right now whether I am right or wrong.... People will get tired of voice overs in dungeons and raids very quickly and the game loses its mass appeal after you have leveled your first character, I see it more like being another KotoR than anything. Fun for awhile but nothing permanent or long term.
My definition of "next-gen MMO" is not a reskined WoW clone with voice acting, and no end game. You may make the argument that WoW didn't have end game when it was released at first, but again a next-gen MMO should be everything the current MMO is plus more. It should have end game. It should have amazing PVP. It should have something that makes it different, and VO with the standard crappy morality system used in every bioware game thusfar is not going to cut it.