I think Wrath is the apex of this curve and if there would be another expansion after this, it would only lead to a decline. http://bit.ly/etF2xB

warcraft must come to an end? Never! I mean, sure World of Warcraft can get outdated, but some people will still play it, and even if WoW dies, there will probably be a second WoW, or a new warcraft rts.
http://bit.ly/fWgi6j