Exactly, it started getting rather dull around GT4 for me and definitely by the PS3 era. I'm not suggesting they should completely change the structure of the game, and I'm aware there isn't as much scope to change things in a racing game as other genres but they could certainly do a lot more than they have to date copy>pasting the same thing over and over.
They seem to completely lack imagination. Just look at the seasonal events. You have all of those cars, in different classes, different formats, different series and what do they usually give players? "Race Car", "Non-Race Car".
Like I say, it appears GTS is indeed going to be different, but we'll have to see how different.