I seriously doubt he's "constantly" thinking of ways to improve the site. That aside, (and I really apologize for anyone interpreting this as a negative comment), I highly respect pg but at the same time, wtf? Are the comments really that bad to deserve this honestly draconian new approach? This might seem like a short-term solution to the "problem" of poor comments but it is not a true solution! Rather, it is a poorly thought out filtering mechanism that doesn't apply merit into the determination of filtering, but instead uses the totally superficial criterion of "karma point count" instead of anything other than a time-based evaluation strategy. I think it only further contributes to the "redditization" of online communities and this inevitably lowers the quality of comments by increasing the barrier to entry of commenters and will over time force inter-comment dynamics into becoming increasingly censored.

Imagine an oldguy commenter with 2400 karma is in a discussion with a newb. He could be prowling the pending comments and could simply flag a newbreply just because he disagrees, thereby artificially making it look like he has "won" an argument even though he has just forced a newbreply into oblivion, despite whatever logical argumentation newb has employed in his reply.

This is bad. :(