Well indeed, I hope they're not sinking much more time and effort into the game at this point, I already 'got over' the fact GT6 would not become much better/different shortly after it released.
But still, there's almost no time required to add a few more things, I don't think they even want to add the course maker, but if they do, they better make the course maker save files transfer-able and compatible with GT7.. just a big waste otherwise to add it now.
Kaz mentioned about how working on PS4 will be like "starting from a new slate".. so really that sounds like they will have built this game from scratch, and would have been working at it with the new dev tools since at least half a year before Sony launched the system, so we hope they've been working every single day at this thing. It just doesn't seem like it since Kaz doesn't like to at least say "yo guys, chill out now, we're working hard at it and please stay patient"..
The franchise will come back to the front, I KNOW Kaz is not taking all the affiliations he's gained in the automotive and motorsports industry for granted, PD must be determined to bring high-standard and professional game as they always have and show a bunch of new features and tech's within the game.