I think people are forgetting that the game can be released whenever they want it to be, but maybe there is a large update to Sony about to happen the the game wont be able to run on some formats of GT Mobile. It has been mentioned before.. Another thing is, if they are adding in more coding, they would want it to be Clean Code, so that the game runs faster.. We've all heard and seen the troubles we have, which can be disc or Sony faults, so why not try to make the game as smooth as possible?
And anyone who would want to harm innocent virtual people stuck on a loop, is inhumane.
Eastley has a valid point, you don't want to be going round a corner, cutting it pretty close to the edge, to hit some random invisible object, and stop completely, only to realize you have a time penalty for hitting the 'invisible object'..
Also NASCAR would be another big thing.. Seeming as it is such a large sport. There would be hundreds of new cars to put in, and maybe you will be able to choose a customary number for your car.
GT5 will be revolutionary no matter what. And the influence it will have on other racing games will be outstanding. It already has had a large impact on sales of EA racing games, and if it's only competition would be the street racing games, like Need for speed, which has been a rival for so long.