Right now, for instance, it's easy to create an arbitrarily high-signal version of LW by going to http://lesswrong.com/prefs/ and changing the thresholds for minimum post/comment scores.
Uh, did not know that. Thank you!
I still have a caveat about posts which are extremely good at getting upvotes having a tendency to be shallow in content, but I think that overall, you are correct.
Ever since Eliezer, Yvain, and myself stopped posting regularly, LW's front page has mostly been populated by meta posts. (The Discussion section is still abuzz with interesting content, though, including original research.)
Luckily, many LWers are posting potentially front-page-worthy content to their own blogs.
Below are some recent-ish highlights outside Less Wrong, for your reading enjoyment. I've added an * to my personal favorites.
Overcoming Bias (Robin Hanson, Rob Wiblin, Katja Grace, Carl Shulman)