I haven't noticed any huge decline in the front page recently, although I do think that many stories scroll off the new page way too fast. This is still a huge problem for longer articles as well as lectures and podcasts, and basically prevents anything but short pithy content from making the front page.
As far as comments go, I think the main problem is that there are just too many comments that don't really contribute much. The other thing that bothers me is there are a handful of commenters who contribute very little of value and yet are some of the fastest rising in terms of karma. I've always been fairly non-sensitive to mean-spirited comments, so whether this has gotten better or worse I have no idea.
edit: Maybe there the new page could be changed to some kind of queue system for non-breaking news, where it would be limited to 30 new stories per hour.
This is how I classify articles (loosely based on a famous quote by Eleanor Roosevelt+):
-Articles on ideas: +1. Examples from current homepage include "Why we moved off the cloud" -- and that's kind of stretching it.
- Articles about events or claims: "meh" Examples: Batch is the best photo editor, google+ now available for google apps, etc
-Articles on other people, current events, activism: Flag Examples: Google police brutality, Vimeo bans game videos, etc. This is more slashdot material, nothing interesting.
*The E.Roosevelt quote is something like "Great minds discuss ideas, average minds discuss events, small minds discuss other people"
EDIT: I realized after I edited my answer that it doesn't really apply to your comment. I meant to say that given this method of classification, it's noticeable that the quality of articles has decreased, and would love to see more ideas than pointless "they're taking our rights" articles.
The quote is not by Eleanor Roosevelt. It goes back to at least 1901, in the precisely titled Reminiscences of Legal and Social Life in Edinburgh and London, 1850-1900. (Discussed at http://en.wikiquote.org/wiki/Eleanor_Roosevelt.)
Also, I don't think it's true. It sounds true because of the way it is formulated. But great minds often discuss all of these things. Think of, say, David Hume. Clearly a great mind, clearly (IIRC) interested in all three.
As far as comments go, I think the main problem is that there are just too many comments that don't really contribute much. The other thing that bothers me is there are a handful of commenters who contribute very little of value and yet are some of the fastest rising in terms of karma. I've always been fairly non-sensitive to mean-spirited comments, so whether this has gotten better or worse I have no idea.
edit: Maybe there the new page could be changed to some kind of queue system for non-breaking news, where it would be limited to 30 new stories per hour.