Earlier this month, Microsoft has released to developers the first major upgrade of the operating system Windows Phone 8.1 Update 1 (GDR1), which has a build number 8.10.14157.200. Today in the database benchmark WP Bench were found information about the version of the operating system under number 8.15.12375.0, which is expected to become the second major update to Windows Phone 8.1 and will be called Update 2 (GDR2).
It is expected that the version for developers of Windows Phone 8.1 Update 2 will be released before the end of this year (the assurance of other sources - in October), and a custom version should not wait until the beginning of 2015.
Presumably, Windows Phone 8.1 Update 2, in addition to the new features is support for display with a resolution of 2K and Snapdragon processor 805.