During the Windows Phone Summit, Microsoft announced that Existing Windows Phone 7.5 devices will be upgraded to Windows Phone 7.8.
Don’t get upset that your device will not be upgraded to Windows Phone 8 because Windows Phone 7.8 still has a lot to offer.
It will come with the new Start Screen that was seen in Windows Phone 8, which includes re-sizable tiles and the removal of the gap on the right side of the Start Screen.it will also feature see new colors for the tiles.
The existing devices are not being upgraded to Windows Phone 8 as WP8’s main features involve new hardware, certain features will not work on existing devices, that’s where WP7.8 comes into play.
Lot more to come.