On December 1, 2011, Google announced a "monthly series on algorithm changes" on its Inside Search blog. From there, Google started posting monthly lists of "search quality highlights," looking at changes (many algorithmic) the search engine had implemented in the previous month. This did continue on a monthly basis for some time.
At some point last year, Google slowed down on putting these lists out. They started coming every other month, with multiple lists released at a time. It's now over a week into February, and we haven't seen Google put out one of these lists since October 4. This is the longest they've gone, by far, since they started doing it.
The lists were an attempt by Google to "push the envelope when it comes to transparency". That's cool. It gives the rest of the web a glimpse at the kinds of things Google is taking into account when making algorithm changes, even if it doesn't give away Google's entire secret sauce (which would likely be he downfall of any search result relevancy).
But where are the last four months worth of highlights?
The last time I wrote a post about Google not putting out these lists, they put one out shortly after. Maybe that will happen again.
One thing is for sure. If Google gets back to putting these lists out, we're going to have a whole lot of info to dig into for the time that has passed.