Hate to break it to you, but while Driveclub is quite good looking, we're not there yet as far as photorealism is concerned.
We still need a much larger poly bugget, more detailed textures, and lighting techniques such as raytracing to be employable in real time with low noise.
And those are just the technical limitations, there are plenty of aesthetic hurdles to achieving photorealism too.
But aside from all that, I have no doubts in my mind that GT7 will be one sharp looking game... ignoring any potential standards that may or may not be present. I think Polyphony will have no problem one-upping Driveclub in the graphics department.