Planet PostgreSQL (https://planet.postgresql.org/) is a "planet"-style blog aggregator showing a selection of PostgreSQL-related blogs. Contributors include PostgreSQL core developers and PostgreSQL users of all kinds.
Snapshot of Planet PostgreSQL as it appeared on 2013-01-29
The nine most recent entries are also shown as headlines towards the bottom of https://www.postgresql.org/.
There's also a Twitter feed, which is useful for browsing through entries which have fallen off the Planet PostgreSQL main page.