Video game based movies always flop. Remember the disasters that were Street Fighter, Mortal Kombat, Tom Raider, Mario Brothers, etc.
I do not hold my breath for a successful BioShock movie.
only one of the above actually has a story that can be made into a full length movie without seriously adding stuff into the plot of the movie from the game. bioshock has everything story wise to go straight from a game to a movie, where the others do not.