A lot of new features in the latest build that was just released, build 17063. Make sure to check out the known issues before updating, as a few popular games (notably League of Legends) can cause a Green Screen of Death.

New features include Timeline, Sets, Fluent Design elements throughout. Check it out!

Known issues

Popular Tencent games like League of Legends and NBA2k Online may cause 64-bit PCs to bugcheck (GSOD).
[DEVELOPERS] Deploying an x86 app to a x64 PC remotely result in “FileNotFound” deployment failures if the target PC is running Build 17040. Deploying an x64 app to a x64 PC remotely or a x86 app to a x86 PC will work fine.
Microsoft Edge may not receive Push Notifications from websites in this flight, due to an issue saving permissions on a per-site basis. We expect this issue to be resolved in the next preview build.
Launching an immersive 360 degree video from the Movies and TV app within Windows Mixed Reality will result in the video facing the wrong way. Subsequent launches of 360 degree videos will work correctly.
When users try to create a Microsoft Edge InPrivate window from inside a Mixed Reality headset, a regular window will get created instead. Users won’t be able to use InPrivate inside Mixed Reality in this build. InPrivate on desktop is not affected.
We’re preparing for the inclusion of OpenSSH Server as a deployment mechanism in Developer Mode. However the UI code got checked in ahead of the components, and so while there is a “Use OpenSSH (Beta) for remote deployment” switch in the UI under Settings, it won’t work, and turning it on will break remote deployment to that device until the switch is turned off.
If you’re using any EUDC fonts Microsoft Edge, Cortana, and other apps that use a webview won’t launch. You can resolve this issue by deleting the HKCU\EUDC key in Registry Editor. Note, if you do this, you won’t be able to see EUDC characters. We recommend you export this regkey before deleting it, so it’s easy to reapply the key in a future flight once the issue has been fixed.
After upgrading to this build you may find touch and pen to not work on the non-primary display. Related to this, mouse, touch, and pen input might not happen in the right place after an orientation change or if you’re using a non-native aspect ratio. We’re working on a fix.