Build release is planned on June 28th but if critical bug is detected, might be postponed.

Major Changes This Build:
Significant performance improvements for low end systems, with simple forward shading support and reflection environment optimizations.
In-game voice chat support.
New Bio Rifle mesh from KazeoHin.
Blitz improvements including improved Rally Cam and gameplay tweaks.
Support character specific first person arms.
First person animations improved and refined.

Full release notes: Unreal Engine Wiki