If you’re already a registered member of the public beta program, or if you’d like to join, just venture over to Apple’s beta website to get going.
To get started with the public beta on your iPhone or iPad, simply log in to the beta program website, and enroll your device. Once enrolled, updates will be conducted in typical OTA style.
Yesterday’s developer-centric release was pushed out with no change log, which isn’t at all out of the ordinary for Apple to do with its minor release versions. There are likely only bug fixes to report in the incremental update.
Are you running the public beta on your iOS device? If so,do you plan on upgrading to 9.2.1?