There had been talk (read: rumor and speculation) that Ghostbusters: The Video Game was coming to the PSP due to the ESRB listing PSP as one of the platforms for the game.
However now Atari has officially clarified that the PSP system listing was a mistake and corrected that this version of the game is only coming to Wii and PS2. They then went one step further by flat out stating to EuroGamer that they have no plans to bring the game to PSP.
Ghostbusters: The Video Game is scheduled for release on Xbox 360, Playstation 3, PC, Wii, PlayStation 2 and DS on June 17th, 2009.