Windows 10 build 17084 is now going through internal testing. The new Redstone 4 (v1803) update build 17084 (10.0.17084.1000 rs_prerelease.180122-1412) was compiled on Jan 22, 2018.
Yesterday, Windows Insider team released a new Windows 10 preview build 17083 for the Insiders.
The latest build brings new features, bug fixes, and various other improvements. Timeline feature is also receiving several new changes in this build to put you more in control of your privacy. However, the latest build also removed the Sets features. You can read more about this build here.
The ISO files for Windows 10 build 17083 are also now available for download. You can download it from the link below.