Really good to see this. SteamOS had a small update recently, which is testing the waters towards a bigger update.
If you've been wondering why SteamOS updates had been so quiet, it seems Valve has been working on updating their build infrastructure. They have another update coming, to finally update the graphics drivers and kernel versions which will also be great to have.
Yesterday's update was just security updates along with package updates pulled in from Debian 8.11. See the full post about it here, here's what they said if you're unable to access at work or wherever:
A lot of minor package updates with security fixes and updates from Debian 8.11[www.debian.org]. As usual, some of the referenced updated packages are only used for building and aren't distributed as part of the SteamOS repository.
We have recently updated our build infrastructure and this update is intentionally kept small in order to test the waters before our upcoming kernel and graphics drivers update.