Apple released macOS 10.15.3 Update, a major software update to macOS Catalina. Update any supported system using the built-in Software, update functionality through the System Preferences pane or by using the standalone installer available from Apple.com.
I've successfully upgraded.
2 Reboots and Done
Everything seems to be ok.
I have clients on Catalina, but haven't upgraded any of my own systems yet. I may just wait until the next major release.