While we wait for Microsoft to release a new preview build of Windows 10 Mobile to Windows Insider members, a website has published some new screenshots of an unreleased version of the OS, build 101134.
The screenshots were posted up on the message board Windowsmania.pl and show off a few new features, such as allowing Microsoft Edge (still called Spartan in this build) to pin sites to the Start screen. There's also an optional dark theme for both Edge and the Windows Store. Cortana now has a new onboard UI in this build. There are also a few more minor changes to wording and UI, such as renaming "Mobile+SIM" in the Settings to "Cellular".
While the PC build of Windows 10 is now set for its official launch on July 29, Microsoft has already revealed that the release of Windows 10 Mobile in a non-preview version won't happen until sometime later this year.