Microsoft has confirmed Windows Phone 8.1 Update 2 "GDR2" for select handsets, including the Lumia 735 and Lumia 830. Availability is currently unknown, but it's in the works.

In order to be able to enjoy Windows Phone 8.1 Update 2 you need to be rocking either the Lumia 640 or the Lumia 640 XL as these are the only Windows Phones with access to that particular release. Microsoft today shared details on Update 2 during a Q&A session at the UK launch of these two smartphones, stating that the update will come to select devices in certain markets.
Read more: Windows Phone 8.1 Update 2 confirmed for select existing smartphones | Windows Central