I'm a bit disappointed that GT6 isn't coming out on PS4, but at the same time GT6 its been in development for a while so I doubt the PS4 design was anywhere near mature enough to develop the game on. If PD are smart though they would have modelled the cars to PS4-level fidelity and then scaled it back down for the PS3, so that a potential PS4 version would just need a tweaked and recompiled engine.
Wikipedia says that GT5 cost $80 million to make and took 5 years, but sales of GT5 Prologue and GT5 are over 15 million combined (shipped), so assuming an average take of ~$25 a sale PD probably took home around $375 million revenue. Given GT6 has only taken 3 years to develop and carried over a lot of content from GT5 I'd guess GT6 would cost in the order of $40-50 million to make, which means profits alone from GT5 would easily have covered the cost of GT6 development. Therefore even if it does sell markedly less (which I think it will), I still think it'll be profitable for PD and Sony, and a good demonstration of Sony's commitment to its consoles even when they are superseded.







