If they make the PS4 standards to at least the "Semi-Premium 2.0" level (like the RUFs, R390, and the Superbird but with very clean textures and actual, next-gen worthy 3D windows, windshields, doors, fully working low/high beam and reverse lights, etc.) then I would be completely fine with that. As long as the visual and audio fidelity is up to par with PS4 standards for the tracks and the rest of the premium cars, I have no problem buying GT7. If they don't deliver on all these fronts though, GT7 will be bargain bin material for me. Revamp the standards to near premium quality or bust.
Again, the career mode and AI are all gameplay factors I really want to see overhauled as well, but the recent partnership with the FIA will likely affect that, so I remain optimistic. If A-Spec turns out to be the same mindless zombiefest, well, there's always online for me.