Hey there. Rockstar,atm plans to release GTA 5 on the PS3 and XBOX 360 platforms. However they dont plan to release the game as a pc game, which personally, is soul destroying as iv always loved the pc version of the GTA series much more interesting and much more fufilling as a game due to graphics advancements and mods etc.
Please if you wish to take part in a petition created by Mike Julliard which will be sent straight to Rockstar, have a look at this and spread the word so that we might just have that GTA 5 on pc yet!