Over the weekend, screenshots and a video of a Nokia Lumia 920 running Windows Phone 8 GDR3 were posted to the WPCentral forums. The original poster, xs2k, says the Nokia Lumia 920 in question is a developer edition device and was bought off Craigslist. The screenshots and video do not add a great detail to what is already known about GDR3, but do provide the first visual representation of many of the new and updated features.

In a separate leak, multiple photos of the forthcoming Nokia Lumia 1520 were posted on The Verge, with the photos sourced from Verge reader KaZ. The photos show the Lumia 1520 alongside the Xperia Z and the device is described as having a Snapdragon 800 processor, 2GB of RAM, 1080p display, 32GB of storage, and a SD card slot.

Windows Phone 8 GDR3 leak

The Windows Phone 8 GDR3 leak shows that the Nokia portion of the software update is named Lumia Bittersweet shimmer. One Nokia customisation that can be seen from the leaks is an update to Nokia Glance Screen (option to be "always on" when charging). 

Other details seen in the screenshots and video include changes to multi-tasking (close icon), driving mode, and screen rotation (locked or portrait). WPCentral also reports that GDR3 will have custom sounds for text, voice mail, email, and reminders (currently only available for calls), the ability to restore a phone over WiFi (currently only over cellular data), and improvement to Bluetooth compatibility with cars.

More information and screenshots are available in this forum thread, with a video of the device available in this WPCentral story.
   

Nokia Lumia 1520 leak

The leaked images of the Nokia Lumia 1520 shared by The Verge tie in with the previously leaked press render of the device. The Lumia 925 like camera bulge is shown close up, and the Start screen is shown to have three columns of medium Live Tiles, providing further confirmation for the Lumia 1520's high resolution screen.

While the leaked images are almost certainly genuine they should be treated as unconfirmed until the formal launch announcement is made by Nokia. The details of the device now seem clear, but it will be interesting to see how the device is positioned, the details of the camera specification, and precise details on the price point and market availability.