Got the update prompt 10 minutes ago, here is the changelog from the official forum:
Bugs Fixed:
System:
- Redesigns Volume UI for android P
- Resolves occasional video playback issues
- Fixes bug incorrect volume control reporting accessibility feature enabled
- Resolves navigation sound issue
- Resolves “Drive address format is not valid” message seen when connecting to NAS
- Resolves USB DAC issue where audio volume would be set low after reboot/DAC hotplug
- Resolves issue where side loaded apps appear as system apps
Display:
-“Match content color space” feature now displays correct format
- Fixes bug where “Match content color space” would not work when display set to RGB
- Resolves issue playing VC1 content
Storage:
- Resolves Sdcard/InternalStorage accessibility issue when adopting storage
- Resolves issue where storage is reported as full after adopting storage
Network:
- Improves 4K streaming issues when network connected over Wifi
- Resolves rare Wi-Fi disconnect issue
- Fixes bug where manual DNS entries would not be saved
Accessories:
- Improves IR control reliability on some Denon and Sony receivers
- Improves SHIELD Remote App connection and control issues
- Resolves SHIELD Controller 2017 OTA stability issues
- Fixes issue where forgotten SHIELD accessories still appear in SHIELD
- Resolves automatic centering issues on some controllers
- Adds support for STRQUA G20 keymapping
- Resolves mouse issues in PUBG Mobile on SHIELD
Misc:
- Fixes Google Play Store crashes issue
- Restores option to set default launcher
Open Known Issues:
- YouTube 5.1 PCM audio not available
- Launcher app Icons appear zoomed/cropped
- Unable to re-enable location services being disabled
- TV loses sync HDMI sync to SHIELD during modesets (power on, wake from sleep, refresh/resolution changes)
- USB DAC passthrough not working in Kodi
- Rare Netflix stutter issue
- Disconnect when connecting to SHIELD from PC
- Failure during 2015 Controller firmware update
Boy I hope this "rare Wi-Fi disconnect issue" that's been fixed is the one that is anything but rare. I'm really tired of all the WiFi disconnects.