First preview Build of Windows 10 for Phones went out yesterday and we have done some good coverage which you can check by clicking here. Now, some more tidbits regarding Windows 10 for Phones from official sources.
Transparent Tiles: Joe Belfiore confirms it will be there in future builds. We have seen a leak on Lumia 925 already.
@OpenPlumbob yes… Were planning to include both the “full background” and “in the tiles” options.
— joebelfiore (@joebelfiore) February 13, 2015
Expect monthly preview Builds form now onwards.
Dark Cortana theme in future Builds.
@cdorf17 Theme support not in this build yet
— Gabriel Aul (@GabeAul) February 13, 2015
Shortcut to use feedback on Windows 10 for Phones