Answer 1:There has been no futher mention of the Cup of Life since it's unexplained 'disposal' in Series 3. Fans believe it was stored in the vaults of Camelot like how the Crystal of Neahtid is stored - but none of this has been confirmed.
Answer 2: The Cup simply.. vanished. And it has not been mentioned again. But since it is such an important artifact, I believe that it was definitely stored. I am surprised it was neither used nor mentioned in the Series 4 though.