Final Fantasy Versus XIII was first unveiled at the E3 gaming expo in 2006. It's now 2011, and the game is not out.
To be fair, Square Enix said in 2006 that it had not yet begun work on the game. But by late 2009, Square Enix was showing gameplay footage of the title. Square Enix would not confirm a 2010 release, and the title obviously wasn't released.