The underlying problem is one of reflection and restraint. Many comments and posts are made very quickly to get the "frist post" or count coup in some other way.
There is a lot more to discuss about the Snowden/NSA brouhaha. It's just not regurgitation of existing bits of information that have already been posted hundreds of times. We burn out on the repetition and get annoyed.
What is relevant, and in my eyes disappointing, is that there has been little deep discourse on the topic. Every article starts at the basic "OMFG" and doesn't take a broader view of new developments.
There is some incentive that is driving the decline of quality content and interaction on the site. Whether it is attention, karma, or whatever, site members have responded with a focus on shallow quantity.
For example, there hasn't been a deep discussion on why privacy is a right. There've been a few comments, such as Schneier's "What's your salary?" that evoke the fear of having privacy violated, but people who are afraid of negative stimulus will override their fear for a more meaningful or important goal. Why is what the NSA doing bad, from basic philosophical principles, and what will the impact be on business, technology, and society in the coming years?
Solving the problem is not simple or trivial, but I'm sure Paul has given many approaches significant thought. It's difficult to implement them without changing the essential simplicity of the site.
There is the Reddit path of subreddits and the various "this thread moved to IYFCategory" forums. I'm not sure that helps. However, there is a natural clustering of some of these topics. While a "politics" cluster is too broad, some shorter-lived and more specialized clusters, such as Snowden/Angular/whatever grouping, would afford discussion among those interested, encapsulate the babble storm, yet give an indication of activity so that individuals can determine their own level of involvement. "I see you're posting a link to a story about Edward Snowden. I'm adding it to the Snowdenball."
Another approach is to limit karma. The people who post karma-bait will top out very quickly and either lose interest, or focus less on the score they have accumulated. It could just be another exponential function of up votes. 1:1 when getting started, then decrease the karma adjustment of each vote over time. Then one has positive and negative feedback, especially among "newer" accounts, and less of a desire even to look at the number past 2,000 or some arbitrary figure.
It's a tough problem. We can self-regulate by avoiding the xkcd 386 impulse. Stop giving votes to shallow thought. Stop posting one-line replies that are obvious and superficial.