This is certainly great news for Windows Phone and Lumia fans. MS is finally showing some urgency and has unexpectedly announced GDR3 before the October 22nd announcement of new Lumia Phablets. Not only they have detailed about new expected and leaked features but also have taken care of one of the major complaints of developers. Now, developers will get early access to per-release builds of the updates before the final roll out.
Also they specifically mentions that the update paves the way for 5-inch and 6-inch devices. Enough hint for 5-inch Lumia 1320 and 6-inch Lumia 1520.
Support for bigger, higher-resolution screens
So the new update paves the way for future Windows Phone devices with 5- and 6-inch touch screens. The larger, 1080p HD displays on these devices will make Windows Phone even more personal—for example by sporting jumbo-sized Start screens with room for six Live Tiles across instead of four.
A bigger Start screen means the ability to pin even more of the people, info, and apps that matter to you. Built-in apps and Hubs like email, Photos, People, and Music and Videos will also be carefully scaled to take full advantage of the additional real estate on 6-inch screens.
More powerful hardware
In addition to larger screens, Update 3 will also bring support for the Qualcomm Snapdragon 800 quad-core processor. The added horsepower that this chip delivers should make our already-fluid operating system perform even better.
A new feature called Driving Mode helps you get from point A to point B with fewer distractions. Working with a connected Bluetooth device, Driving Mode is designed to limit notifications on the lock screen—including texts, calls, and quick status alerts—until you’re safely parked.
New accessibility features
Another highlight of the new update is Mobile Accessibility for Windows Phone 8, which isn’t a single feature but a suite of apps designed to make Windows Phone easier to see, hear, and use. The apps, which include a screen reader, make it easier for blind and visually impaired users to manage calls and contacts, send texts and emails, browse the web, make Skype and Lync calls, and hear notifications like alarms, calendar events, and low-battery warnings.
Improved Internet Sharing
Many of you are familiar with the Internet Sharing feature, which turns Windows Phone 8 into a mobile hotspot by sharing your cellular data connection over Wi-Fi.
In Update 3, we’ve made it easier to use your phone as a data-savvy hotspot for Windows 8.1 devices. Just pair your phone and Windows 8.1 PC or tablet over Bluetooth, tap your network name, and you’ll be connected and ready to go. No need to enter a password or dig out your phone and turn on Internet Sharing—it’s done for you.
More useful ringtones
With Update 3, you can use custom ringtones for more things—including instant messages, emails, voicemails, and reminders. You can also assign custom ringtones to contacts for text messages, so you’ll know who’s texting you without even looking.
No more twist and shout
:Does your screen keep spinning when you’re trying to read emails in bed? Use the new rotation lock option to keep it fixed in place.
Better storage management
New storage settings make it easier to free up space on your phone and manage temporary files. A new category view shows what’s taking up space at a glance.
Easily close apps
Now you can use the App switcher to quickly close apps when you’re finished with them.
Wi-Fi access out of the box
You can now connect to Wi-Fi during phone set up, so you can start conserving cellular data right out of the box.
The team made a bunch of improvements to improve connection quality for Bluetooth accessories.
As for the update roll-out time to your phones, the article mentions,
So when will all this be coming to your phone? As I mentioned earlier, the rollout initially kicks off in the coming weeks and will continue over several months. Specific timing depends on a number of factors including your carrier and phone model.
Developers, click here