I can tell you, I dont think GT4 will do as well as 3. Just a few weeks after its release it sits on our shelves and nobody is looking at it. I know this is just one store in a small town, but still, that's not a good sign. I think they did GT3 so well, that they can't outdo themselves and people are affriad it will be bad.
Thats a possiblity , but maybe people are just busy buying other stuff right now and they figure they can get GT 4 later for less
I know I will wait for a price drop.