Preview at WWDC likely in June, followed by September launch.
Apple Seeds Second macOS High Sierra 10.13.2 Beta to Developers
The macOS High Sierra 10.13.2 beta can be downloaded from the Apple Developer Center or through the Software Update mechanism in the Mac App Store with the proper profile installed.
It's not yet clear what improvements the second update to macOS High Sierra will bring, but it's likely to include bug fixes and performance improvements for issues that weren't addressed in macOS High Sierra 10.13.1.
The previous update, 10.13.1, introduced fixes for some serious security flaws and brought new emoji to the macOS operating system. No new features were found in the first beta of macOS High Sierra 10.13.2, but we'll update this post should new features be found in the second beta.