Last week Microsoft has announced that they are working with their hardware partners and very soon will release Windows Phone 7.8 update. Microsoft has said that update will be available in 2013.
But few hours ago Windows Phone 7.8 update with build 8858.12560 for NokiaLumia 510, 800 and 900 has been leaked on NaviFirm. This leak allow users to update to the official version which is still due from Microsoft and Nokia.
Users who had updated has reported that they had got every new feature which was reported like :-
Resizable Live tiles
New Store Icon
Ringtone Maker, App Highlights, Contact Transfer etc.
Lock screen wallpaper option for Bing
More Accent colours
24 Lockscreen Backgrounds (doesn’t appear in the gallery)