The next major installment for Steam OS is now in the Preview Channel, which is available from your Steam Deck Settings Menu -> System -> Update Channel
Before you go switching channels though, Preview is the early testing phase and expect to hit a few issues before it moves into Beta and then full release.
We'll be taking a look on the channel very soon at the differences but for now, here's what was released:
General
Updated to a more recent Arch Linux base
Improved pairing experience with Apple AirPods
Improved session recovery speed after GPU crashes
Fixed some connectivity failures with access points supporting WPA3 security
Updated Linux kernel to version 6.5
Improved speed of subsequent OS updates
Improved reliability of certain microSD card usage scenarios
Fixed game session cursor offset alignment
Worked around misdetection of some SanDisk microSD cards
Fixed an issue where a thin grey line could appear at the bottom of the screen during boot in some situations
Fixed an issue causing temporary files to accrue when using Flatpak
Enabled support for Bluetooth A2DP and BAP profiles
Improved connection speed of some Bluetooth devices
Improved performance and stability in memory pressure situations
Fixed an issue where the Performance Overlay would spuriously enable itself under certain conditions
Added mechanism to configure which Bluetooth device categories are allowed to wake the system from suspend
By default, controllers are the only devices that can wake the system from sleep
Finer-grained UI configuration options will be available as part of a future update
Display
Improved display uniformity, under some conditions (Mura Compensation)
Improved display color balance (reduced green tint) at lower brightness levels, under some conditions
Improved gamma uniformity (yellow tint), under some conditions
Graphics and Performance
Updated graphics driver to Mesa 24.1, with many performance and correctness improvements
Improved responsiveness of the Steam UI
Desktop Mode
Updated to KDE Plasma 5.27.10
Enabled thumbnail previews for videos in the file browser
Fixed an issue with desktop use that could cause subsequent microSD card auto-mount to fail
Deck Dock
Added support for some HDMI CEC features:
TV remote input
TV wake up
TV input switching
Updated Dock firmware, with compatibility fixes for high-refresh-rate VRR displays
BIOS
Added overclocking controls on Steam Deck LCD
Fixed not being able to set the SDCard as default boot device
Adjusted power LED slow charging threshold
Fixed spurious power LED blinking in S5
Development and Modding
Modified files in /etc are now migrated to new OS versions based on a whitelist
Fixes numerous issues with incidentally touched /etc files becoming 'sticky' and persisting unexpectedly
Additional whitelist entries can be added via config fragments
See /etc/atomic-update.conf.d/example-additional-keep-list.conf
Added /etc/previous/ containing modifications from the previous update to prevent unexpected data loss
Up to five previous snaphots of /etc modifications will additionally be retained in /var/lib/steamos-atomupd/etc_backup/
Added support for {ssh,sshd}_config fragments
Known Issues
Frequent session switches can result in the sound driver crashing, needing a system reboot
You can follow the news directly on the Steam Store here