After releasing build 10586.456 to Windows 10 Mobile earlier today, Microsoft has now pushed the latest Release Preview build to Insider's on Windows 10 PC.
The release was announced by the Windows Insider Twitter account:
Windows Insiders in the Release Preview ring: Make sure you check out the new 10586.456 update! Available for both PC and Mobile!
— Windows Insider (@windowsinsider) June 29, 2016
There is no changelog for this build unfortunately, however, it will contain the usual bug fixes and performance enhancements to fix reported issues by Windows Insider's.
If more information on the build becomes available, we'll let you know - until then, you can head over to Settings > Update & Security to begin updating your PC.