It's not obvious to me how to automatically classify stories as (a)temporal. My understanding of the way submissions work is that if Bob submits something that Alice also recently[1] submitted, then it just gets counted as an upvote for Alice's story.

Then, of course, there are the "this happened recently, which inspired me to think about some broader trend". For example, during the AWS outage, Coding Horror had a story about Netflix's Chaos Monkey[2], which one could easily classify as both temporal and atemporal.

[1] For some definition of "recently" that I haven't yet figured out. [2] http://www.codinghorror.com/blog/2011/04/working-with-the-ch...