On Wednesday, Apple seeded the tenth beta version of macOS Big Sur to registered developers.
The newest beta can be downloaded from the Apple Developer Center by those in the Developer Beta program, or as an over-the-air update on devices with the proper configuration profile installed.
For macOS Big Sur, Apple’s main goal is compatibility with Apple Silicon, along with current Intel processors. Other improvements are naturally included for both processor types, such as design elements within Safari and Messages becoming a Catalyst app.
The iPhone 12 event has come and gone without any Apple Silicon Mac release. November seems likeliest for Big Sur’s release.
AppleInsider, and Apple itself, strongly suggest users don’t install betas on to “mission-critical” or primary devices, due to the potential for data loss or other issues. It is instead recommended to install betas onto secondary or non-essential devices, and to ensure there are sufficient backups of important data beforehand.