as far as i am aware it is very doubtful it will, Playststion and Microsoft have exclusive rights for it
Remember who makes the close to 100% dominant operating system for gaming on the PC....
The main reason theres no PC port announced is that while all the other GTAs had them, they ran on Renderware and this one runs on RAGE - and theres no PC version of RAGE. Wouldn't be too hard to port it as the XBox360 runs something very close to Windows with almost identical graphics setups, etc.