I think the inability to vote topics down avoids some of the problems that Reddit has encountered, where people camp out and vote submissions down in order to make their own appear higher. I think a more mature (on average) user base helps to accomplish that as well.
Finally, I think that most people must have heard of YC news through either pg's site or through YCombinator itself. Anyone interested in those two things are cool in my book, and should produce good discussions.
Edit: Maybe they've banned them now; the new queue is currently clean.
in todays el-explosion'ary 2.0 scene simple is usually left out
there are no tags, avatars, profiles, subgroups, contacts, thingamwhos and fake promises
Now that I've removed that step from my workflow, I check much less often. :-)
what i find in yc news: inspiration, fresh, new, professional development, stuff to think about, its almost a good excuse for browsing vs say drudgereport,
i see alot more 2.0 newness mentions as well, i usually go to emilys hub for that
it feels more fresh, and i feel like it matters more than random dude check this out digg like stuff
(danw, remember I asked this about justin.tv, and the answer turned out to be about 18 hours after I asked...)