you know, they do upgrade the graphics over time.
to anyone who's played GT4, its clear that these images are taken from inside the photo mode in the game. just like in GT4, there's a whole lot of different settings to play around with in the photo editor, such as shutter time and those kind of things, but AA is always applied. -thats why these pics look way smoother than when you're actaully playing the game.
the photo mode does not apply any other graphical improvement...
yeah the jaggies definately remove a big part of the wow effect. sadly, i dont think they can do much about it, as every other PS3 game with same kind of lighting effect (what's it called, dynamic lighting?) has the same low shadow resolution as GTHD. its just like AA i guess, makes alot of difference, both in image quality, and required hardware power.