Joey Kudish assisted in its creation, and describes the API as, “pretty simple and simply pulls a curated list of plugins (literally powered by a text file) and fetches data for those plugins using the WordPress.org plugins API.”
They are asking for testing and input from other developers. You are also free to fork the code to create your own set of recommendations. I'd be interested in a more formal approach for a curated plugin list — especially one that includes plugins outside of the WordPress directory. There are tens of thousands of plugins, but a tiny fraction of those are really applicable for the majority of sites.