When Microsoft released build 9860 of Windows 10, they introduced a new 'slow' and 'fast' release cadence that allows you to determine how quickly you want to receive builds of Windows 10. The difference is that those in the 'fast' ring are willing to accept the faster builds knowing that there could be significant bugs or other issues that make the build unstable for being among the first with the new features.
The 'slow' ring is for those who want to try out the new OS but want a bit more stability with their install. Seeing that 9879 hit the 'fast' ring a few weeks ago, it gave Microsoft time to fix a BSOD issue before pushing it out to 'slow' ring users. After the hotfix went live earlier today, it was only a matter of time until 'slow' ring users got their hands on the build.
And that's exactly the case as Microsoft has announced that the 'slow' ring users can now download 9879. If you don't want to use the built-in update feature to obtain the bits, you can grab the ISOs here.
Source: Gabe Aul