The sheer quantity may be unprecedented, I confess: never before has a game company canned a product line by releasing three hardbound game books, a series of paperback novels, a new bunch of cards for their otherwise-moribund CCG, and a computer game.
However, it's not the first time a game company has ended a game-line within the context of its own uber-plot. West End Games did exactly that with their cross-genre "Reality War" game, Torg.
The final release for Torg was "War's End", which brought an end to the major plot thread that drove the overarching story of the game. The Big Bad Villain of the piece was about to gain Ultimate Power, and...
...and here's the difference between Torg and the WoD. In "War's End", there's an Ancient Evil Entity about to achieve something that transcends even his current near-divine state -- and the Player Characters play a vital role in whether or not he's stopped.
In the WoD, things like that are far too important to be left to the hands of the PCs. They get to just stand around and watch, knowing that all they've done over the last twelve years didn't really accomplish anything to ward off (or hasten) the GehennapocalypscensionTM.
In some RPGs, you get to do things. In others, things get done to you.