I was going to point out that a 4.2 Preview build was uploaded two days ago, but no bother. A few minutes ago the 4.2 Release](https://github/EpicGames/UnrealEngine/releases) was put up on Github. Enjoy. 
Per 4.3, it’s on a separate branch and I doubt its timetable would be affected by the 4.2 release.
Cheers,
-D