From the official blog post:
Thanks for being patient with us as we upgraded some of our engineering tools last week. Our build monitoring system is purring again and today we are excited to be releasing Windows 10 Insider Preview Build 14926 for PC and Mobile to Windows Insiders in the Fast ring.
What’s new in Build 14926
Updated Wi-Fi settings page (Mobile): As part of our experience of unifying the settings experience across devices – we have updated the Wi-Fi settings page via Settings > Network & wireless > Wi-Fi on Mobile to match how it works on PC. The new Wi-Fi settings page isn’t complete yet as we continue to port over functionality. If need, you can fallback to using the Wi-Fi (legacy) settings page to access any missing functionality. In addition, we added the capability for you to connect to WPS (Wi-Fi Protected Setup) networks on your phone.
Other improvements and fixes for Mobile
- We fixed a scaling issue on devices such as the Lumia 635, 636, or 638 where the bottom of certain apps, like Messaging and Maps, would get cut off and rendered off screen.
- We heard you and we have addressed the largest cause of reliability issues in Microsoft Edge running on Insider Preview builds. This should improve reliability on major websites such as Facebook and Outlook.com.
- We fixed an issue resulting in the sound of key presses and lock/unlock being barely audible when the phone was using a moderate volume.
- We fixed an issue where, if Quiet Hours had been turned on, banner notifications might not start appearing again until Action Center was opened or an interactive notification popped up and was dismissed.
- We fixed an issue where Cortana would crash when trying to open Reminders page.
- We have improved the reliability of VPN Settings page via Settings > Network & wireless > VPN.
- We fixed an issue resulting in the thumbnail for portrait videos displaying with an incorrect aspect ratio in the Photos app when panning through the Camera Roll.
Known issues for Mobile
- Some devices such as the Lumia 650 will fail to install this build with Error 0x80188308. We are currently investigating this issue.
- Action Center no longer closes if you swipe up on the empty space (area of Action Center that doesn’t show any notifications).
- Using your phone as a mobile hotspot will work the first time but subsequent attempts to use the feature will result in the inability to enable the hotspot until the phone is rebooted.
All my Fast ring devices are downloading and updating as I write this.
Of course, in the fulness of time we'll need a summary of what's new going from Redstone to Redstone 2, but we won't have a full feature set or changelog until at least Christmas 2016. Settle down for the long haul, everyone....!
PS. How cool is is that the main Wi-fi network used as an example in the screenshots is named 'Holodeck'? 8-)