Yeah it is, i would argue that GTA games have always created benchmarks for consoles and systems and gta4 is definately the first game arguably that truley utilises and pushes this current generation of hardware to its limits.

I went to a presentation at a games fair where the people who are providing the physics engine for the game spoke about the engine and how it was developed. It bassically started as a program to create intelligent creatures that could walk under the forces of our planet, ie gravity, wind.

they built muscle denisty, gravity and whole range of things into the program so that the characters actually react to ingame events using natural motion and true physical weight.

its really amazing and this is what gta runs, at the presentation he played a tiny snippet of the game, he said he shouldnt, but as it wasnt rendered it should be ok. its amazing, cars are true weight to them and move accordingly and the people actually interact with the floor, rather that floating over a glass one.

plus then all the new facial animations.

i could go on

anyway the website for the company is NaturalMotion

you can download a trial program and do all kind of crazy shit, just type in endporhin in youtube for loads of home made stuff.

i have to admit i love mgs so i might have to buy a ps3 just for that

peace