Back in 2014, a question was posted, asking "What's new in TeX, version 3.14159265?". I know that the upcoming version of TeX will have at least one important bug fix, and I think it would be nice to have a corresponding, moderator-sanctioned question. I don't believe the earlier question was planned by the site, but as far as I am aware tex.se has been around to witness only the one update. I'd also suggest that a single, official "What's new" post be made for each new update henceforth.
(I hope I'm not out of line here. The 2014 question and egreg's answer were key factors in my getting interested in TeX. And there may be some interesting changes in this update.)