Microsoft has released Windows 10 Insider Preview Build 20279 to Windows Insiders in the Dev Channel. This build is largely the same as Build 20277
Interestingly according to Microsoft Windows Insiders who updated to Build 21277 (RS_PRERELEASE) last week will not be offered this build as they are on a newer build.
There are a few known issues. You can go through the details here
mceworld 