Microsoft has now pushed Windows 10 Redstone 4 Preview Build 17074.1002 to insiders in the Slow Ring. The last build for Slow Ring was Build 17025 pushed on November 2 by Microsoft. So, naturally there have been a big number of changes and addition of new features with subsequent preview builds until the Build 17074.1002.
You can read the complete categorized changelog of all Redstone 4 builds so far by clicking here. If you are interested in build-wise coverage, click here to read changelog of the all the builds from Build 17025 to 17074 by clicking here.
In case you want to do a clean install of the Build 17074.1002, click here to install 3rd party ISO images