I think it's already been well-established that if GT4 isn't the best game of all time or best racing game of all time, at least it will be the most complete GT game. But don't expect PD to drop the franchise and try something people won't like. I think GT4 will probably do a better job of capturing as much history as possible. To me, GT2's car lineups are about to get owned, devoured, flushed down the toilet... whatever terminology you prefer. Like imagine if you can race a Sauber Mercedes from 1989 around Grand Valley, or that sweet Nissan GTP racer from the early 1990s around Paris like in the pictures.
And that Kei car in one of the pictures... it would be nice to have a few more little cars. I mean, I don't care about having all mega-horsepowered cars, but it would be nice to find a wonderful performing car that has low HPs compared to the... okay, I'm almost saying the same thing twice here! Anyhow, someone was talking about getting rid of the Kei machinery in another thread. Of course, the ultimate small car has the be the Mini Cooper, and I hope GT can really highlight on this little baby.
And as far as the Milk Truck goes, you might get your wish. With all due respect to this car, you may get it in the form of the Toyota Bb/Scion Xb. If not that, what about a Chevy SSR delivering milk to thousands of dateless losers (like me, but I'm no loser)? Milk trucks are possible! Or what about a Hummer H2 converted to a garbage truck running up the streets of Paris? You might even get a school bus that has a Stage 4 and can be only 20 mph short of the Renault Espace F1's top speed. Okay, maybe I'm having a little too much fun here. Don't want to get any "n00bs" blood pumping with faux pas (false) news.