There's a few useful changes in this build, along with the usual skew of bug fixes (and new bugs, this being a fairly early RS_4 build). Highlights include:
- Yet more changes for Edge - this time you get the ability for Edge to auto-fill address info on forms.
- Access to UWP applications (Metro apps to you and me) settings directly from the application icon in the Start Menu. This is way, way simpler than the old Settings > Apps & Features > App > Settings route you used to have to take, and a big UX win.
- Yet-more emoji changes. To be honest, these bore me - they're hardly core-OS functions.
Here's the full MS release notes: https://blogs.windows.com/windowsexperience/2017/11/22/announcing-windows-10-insider-preview-build-17046-pc/#j8WGYt6Wkvq76y4i.97