Apple released the second developer beta of MacOS Catalina 10.15.1 on Thursday. No major new features have been uncovered in Catalina 10.15.1, but Apple is adding support for AMD Navi RDNA video cards for eGPUs.
macOS Catalina 10.15 was just released on October 7th.
Developers can register their Macs for the developer beta program at the Apple Developer Connection. If your Mac is already set up for Catalina developer betas, you’ll find the update in Software Update.