SpaceX will be doing a Pad Abort test at LC-40 in Florida for the Dragon V2 vehicle to close out the CCiCAP criteria.
They will not be using a real first or second stage, instead building some kind of truss to hold the Dragon V2 at about the right height and then trigger the abort from there.
Perhaps the test would destroy the second stage, but why not use a real first stage, mount an appropriate space to represent the second stage, and then do the abort?