I’ve often added material to recent posts as “updates”, while aware that some who might be interested would likely not realize the added material was there. To improve the situation, I’ve just added a “Recently Modified Posts” widget on the right. The ordering is by modification time. I’ll try and figure out how to avoid having the modification time change when I do something like fix a typo (right now some old film reviews are appearing on the list because I recently added a “Film Reviews” category).
Among recent updates, I recommend the updates to this posting. Someone pointed me to a quite remarkable exchange earlier this week between Mike Peskin and Nima Arkani-Hamed.