You know what gives SC1, WC3, and SC2 so much longetivity? Custom user maps.
You know why you shouldn't say that's "simply untrue" or any variation thereof? Because that would make you look extremely ignorant, so please just keep reading.
The aforementioned games all had map editors, and WoW should have a similar system for quests and dungeons/raids.
People could create their own "Fall of Silvermoon", "Beyond the Dark Portal", "The First War" quests and encounters and PVP maps and whatever else they could think of, and it would give people things to do and things to play.
I see people all day long the MMO C forums claiming they're old school Warcraft fans of the RTSs and blah blah, well if you actually are, I'm sure some of you besides myself would like to create/recreate some of their own stories through WoW.
On top of that, you'd have current Blizzard patches that would advance the present day content and lore, but when people would finish that, they'd have something else to do.
Now go ahead and inspect my previous posts and threads and make ignorant comments about how this is a stupid idea because of unrelated things I've said in those posts, and eventually close the thread. Good day.