It's Aaron Greenburg who's been hyping up this game not Bungie. Bungie's not like Greenburg, trying to hype shit up and diss other competitors.
And I'm sure Bungie only released something of an old build of Reach not an up to date build of Reach and yes I agree with you that currently it's got nothing on Killzone 2 and Uncharted 2 graphics but then again it's unfair to compare old build stuff to fully finished and polished games.
So maybe when Bungie decides to release real up to date build screens and trailers of Halo Reach, that's when you can really decide whether Reach is on par (but not exceed) with Killzone 2, Metal Gear Solid 4 or Uncharted 2.