It was hyped,not as much as your all suggesting.
But the crucial thing is that it lived up to the hype.Killzone 2 may not be as widely accepted as Modern Warfare 2,or even Uncharted 2 on the PS3.But Killzone offers a more intense experience than modern warfare 2 and a completely different experience to Uncharted 2.
If you want truly hyped games that I personally think did not live up to it,GTA IV and HAZE are the big ones for that.And Too Human on the 360,that's had like a decade of hype put into it.