The content of Forza was irrelevent to the point I was making but since you felt the need to go into a defensive rant about Forza forget about that. Think about the jump between GT3 and GT4, that is what I'm expecting from GT6 on the PS3.
As I've said in the other thread, there are so many aspects of GT5 that can be improved upon that have nothing to do with the console limits and everything to do with time limits. For example you say you want Nurburgring 24 experience on all tracks, I assume you mean weather and night? Well that's entirely possible given more time, they can add that to all of the tracks. Don't need new hardware for that. Same goes for adding all of the tracks they removed from older games, the only limit on that is time converting them and space on the disc, which I believe for GT5 was plenty.
You don't know that at all, you're just guessing. A PS4 hasn't even been announced and isn't likely to be soon. Also, what exactly is "Kaz's new vision"?