imo, yes, the quality/type-of/whatever of submissions has become very different from what it was 2 years ago. but then again, that's a subjective analysis.
but imho tags/categories are awful. there has to be a better solution to this.
i don't think filtering domains will do much good either.
editors like slashdot aren't exactly great (and require an editor staff).
voting schemes reflect the taste of the community (more specifically the percentage of people that vote - not taking into account bots/cheaters). there's always slashdot's semi-random karma system, but it's not really that great either.
so really, what's the solution? no effing clue..
-----------------------------------
on the other hand, i'd really like to know the stats on the number of people who click on an article and the number of people who voted on the same article..
also, average points stories get and so on..
edit:
oh yeah, nevermind that, forgot that only after some X karma you can downvote/flag
-----------------------------------
oh well, information overload.. it's a joy