PSU quotes issue 190 of the magazine as stating: We're not talking about new DLC or a collection of previously available DLC, we're talking about a full retail game. We expect this title to follow the suit of previous GTAs and use a subtitle such as GTA: San Andreas. Tokyo might be a possible setting for the game, but details are non-existent at this time.”
PSU goes on to say that it wouldn't be surprising for RockStar to release the next GTA this soon – as you may recall, Vice City hit the shops only a year after Grand Theft Auto III was released for PS2”.
However, with the development hours needed to complete a game of GTA's scale on next-gen consoles, 18 months would seem like an exceptionally fast turnaround – particularly if the next title is to be set in a brand new location.
MCV has contacted Rockstar for comment.