I saw The Mortal Instruments: City of Bones and I was really confused by the ending. It seemed to me that they gave up the Mortal Cup a bit too easily and there was some hints that it wasn't real, what with the replica that Isabelle showed Simon at the beginning seeming to be a Chekov's Gun (much like the card with the cup on it wound up being) and Valentine receiving the cup from Hodge and saying that he had to make sure it was genuine (foreshadowing?). Plus Clary had the card at the end.
However, they never outright said "It's a good thing that we gave Valentine the fake cup!" So did Valentine get the real thing or not? Is this something they explained in the book?