I think that stuff like a fully immersive career mode needs to come AFTER they perfect the fully immersive driving experience!
Not much point to the eye candy if the handling still needs a lot of fettling, or the AI is all over the shop, or collisions still bounce things around like rag dolls, etc..!
My favorite things from PC2 were the pre-21st century vehicles and tracks. Not really because I'm nostalgic, but more that those kinds of tracks and cars tend to lend themselves to good racing and good driving technique. I don't think it's a coincidence how popular GT3 cars are with the noobs. Yes, they're seeing the same cars they're currently seeing on TV, but they're also damn easy to drive up to close to the limit.
20th century race cars sort out the drivers from the rookies pretty early in a race!
On a different note, I sometimes wonder how good PC2 could have been if SMS had have done what S4S have done and just basically stolen and renamed all the tracks to avoid license payments? If every penny spent on licensing tracks had have gone to the development team, would it have been enough that Bandai didn't bail, and PC3 had simply been more of the same?
We'll never know, but it's comforting to think that almost everything coming in (which probably ain't a lot currently!) is at least going to the areas of the game that need it most. I don't need or want photo-realism for every billboard, but I'd sure like my cars to handle realistically and my AI to give me a balanced challenge each race! And we know getting that takes money that often gets used to pay licensing fees...