E3 2005 gave people the infamous MotorStorm and Killzone 2 trailers. They looked amazing - too good to be true. And of course, they were too good to be true, generated as 'target footage' by Sony. MotorStorm came close (sort of) but failed. And now GamesRadar has got playable preview version of Killzone 2 sitting in theirr PS3, they can tell you that it doesn't look as good as that early footage.
It looks better.