Gran Turismo 6 is currently in some stage of development per an interview IGN conducted with Polyphony Digital’s Kazunori Yamauchi.
During the interview, Yamauchi directly addressed the next iteration of Gran Turismo when asked about it rather than skirting around the question. “Of course we’re working on GT6 already and I think what really will be the separating factor is something that we can’t update through a DLC is something that obviously has to be saved for GT6,” Yamauchi said. “Things that we can provide through DLC we will, so that’s really the market difference.”
As history has taught us, Polyphony Digital takes many years to produce a new installment of Gran Turismo and is still working on new DLC for Gran Turismo 5. Sony’s Playstation 3 is currently in the latter half of its life-cycle and could be replaced by as early as 2013. Put two and two together and the odds slant toward Gran Turismo 6 speeding onto Playstation 4 (or whatever Sony chooses to call their next console) rather than Playstation 3.
Source: IGN