I had a go on this yesterday. I set the fastest lap of the day, which gets me a free copy of the game.
the fastest of the show gets a limited edition PS3 and Collectors edition GT5 bundle. i was 2 secs off that which was set by "a professional racing driver", but only being able to set 1 lap, on a completely new track (Rome), it is achievable to beat him by a second or so.
I'm going back on Wednesday night to have a proper look at everything there (did a rush job on sunday) so i will have another go then.
From what I could tell, and after having just come back from the states and playing the Best Buy demo also, this build is nothing new.
Physics are improved over GT5 TT demo, and weight transfer plays a huge part in handling now. (brake while turning or out of shape and your spinning.)
I'll post more up after i have another go on wednesday.
Josh