During Windows Phone 8.1 development and internal beta testing many new features were added to Windows Phone 8.1, and I leaked most of these features on Twitter and here in the Windows 8 group.
Almost all the features I leaked are coming in the final version of WP 8.1 and they will be available in the WP 8.1 Preview which will be released on April 14 as planned. The Preview is almost the final version and it is feature complete.
But some features I leaked before are not coming in WP 8.1 which includes:
1. File Manager (http://twitter.com/Nawzil8/status/407435667568750592)
2. USB OTG (http://twitter.com/Nawzil8/status/444548908258443265)
Both of these features were there in the internal beta builds of WP 8.1 and they worked perfectly as I described in the tweet. But they are removed from the final version of WP 8.1 for unknown reasons. These features may come later in WP8.1 Update 1 or Update 2 as leaked by a Microsoft employee some days ago.
On November 15, 2013 I leaked a photo showing more tiles on an internal beta build of WP8 Update 3 (GDR3) on Lumia 920.
But that didn’t come with the final version of WP8 Update 3, and it is coming with WP 8.1
As I said above WP 8.1 Preview will have all the features of WP 8.1, but some features will not work on Lumia phones without the Lumia Cyan firmware update.
These features include:
1. Wireless Miracast (Project My Screen)
2. Bluetooth 4.0 LE
So we will have to wait until Lumia Cyan is officially rolled out to our Lumia phones to use those features. Some of these features (1 and 3) will initially be available to phones with Quad Core processor only.
(Source: Nawzil Najeeb)