Wrath will go down that retail path.
I will be surprised if Blizzard stops Wrath.
I think and yes just my opinion Blizzard will make all expacs as a stand alone game.
Retail will advance but as it does players unsub.
By making all expacs stand alone game it will keep players.
Everyone has their favorite expac and some have found a new one.
Just thought of this.
Blizzard can only make Wrath better than the private servers,
If Blizzard changes to much people will go to private servers to play.