Among the other responses, I noticed a number with the post-rational theme that we ought to worry about the ways we worry—because of the way our minds are organized, these writers think, we can't fret about the right things, even as we wear ourselves into a frazzle about the wrong ones.
For instance, Dan Sperber worries that we generally worry in ways that are futile but wasteful of our limited time and energy.
Another "meta" theme this year is the unexamined consequences of the human race's process of taming itself. For instance, Scott Atran worries that the rich variety of human experience is turning into one homogenized global beige, the way that the planet's rich diversity of edible plants has been crowded out by a few monocultures. And Nicholas Humphrey worries about the ease with which people now access any knowledge they seek.
I was also struck by Alison Gopnik's worry about our misplaced notions of childrearing, which causes people to worry about inconsequential things (which way the stroller faces, which form of "sleep training" to use) while missing the consequential ones (like the fact that so many American children grow up in poverty, thus missing out on the "long, protected, stable childhood" that best serves a developing human being). That one ties together the threads of misplaced anxiety, reliance on technology, and the effects of today's experiences on tomorrow's people. It also is one of those mind-altering posts which causes you wonder "how could I have not seen that?"
All in all, it's a stimulating collection. Well worth a look.