Steam is asking DEVs & publishers to Review Their Game’s Mature Content Survey.
New questions and an updated process now generate ratings for players in Germany
(also applicable to Brazil censorship).

https://gtm.steamproxy.vip/groups/steamworks/announcements/detail/3645136992391096609
(Includes a link to the discussion page at Steamworks Development)

Part of (there's more but not relevant here) the latest Steam Client Beta update:

General

• Added UI that temporarily replaces the "What's New" section of the Library when pre-purchased games are available to pre-load or install and play
  
• Added UI at startup for account selection
  
• Added a "sign out" option to the main menu that removes credentials for the signed in account from the machine

Local Network Game Transfers

• Added new feature that allows Steam users to copy existing Steam game installation and update files from one PC to another over a local area network, without having to download and install from a Steam content server on the internet. This reduces internet traffic and can speed up installs or updates.
  
• This feature is currently only PC -> PC or PC -> Steam Deck, and both sender and receiver must be opted into Steam Beta.
  
• Steam users have control over who files can be sent to: self only, friends only, or everyone. The default setting is self only.
  
• More info about this new feature can be found here: https://help.steampowered.com/en/faqs/view/46BD-6BA8-B012-CE43

In case one would ever want to watch the new Replay pages, you can find them in the store underthe drop-down menu of "New & Interesting" or https://store.steampowered.com/replay/{your Steam ID}/2022

Steam Mystery Fest
View full event information for DEVs & Publishers here:
https://gtm.steamproxy.vip/gid/103582791433666425/announcements/detail/3524658636207210572
Feb 20 - 27, 2023
this event is for games focused on the spirit of investigation and solving mysteries.
Intended victim

Event Dates
Nov 22nd to Nov 29th 2022: Steam Autumn Sale
Winter Sale: Dec 22nd 2022 to Jan 5th 2023
Spring Sale: March 16th to 23rd 2023
&
Base Builder Fest 23 Jan 2023
Next Fest 6- 13 Februari 2023

Originally posted by Quint the Alligator Snapper:

Does the new Big Picture Mode depend on browser-based rendering?

(i.e. does it break when the client is launched with -no-browser)

I don't know, not opted in.

(and sorry for skipping the update for mobile phones, guess i wasn't quite awake that day)

https://store.steampowered.com/news/app/593110/?emclan=103582791457287600&emgid=3394051164709183116

Might be confusing: it's meant for the Steam Deck, although one should opt in via Steam Client Beta program while the discussions have to be brought to the Big Picture forum.

DEV/publisher info: https://gtm.steamproxy.vip/groups/steamworks/announcements/detail/3289340571611574692

October 25 - November 1, 2022: Steam Scream Fest (Halloween)
Nov 22nd to Nov 29th 2022: Steam Autumn Sale
Winter Sale: Dec 22nd to Jan 5th
Spring Sale: March 16th to 23rd

No more Chinese Newyear Festival, that'll be replaced by the Spring sales. DEV/Publisher info: https://gtm.steamproxy.vip/groups/steamworks/announcements/detail/3282583269823858401