AT&T's Nokia Lumia 900 gets Windows Phone update3
resizeable tiles. To change the size of the tile, a long press on it will do the trick. The update also bring new theme colors and improvements to the lock screen. The Bing photo of the day can be used as wallpaper and after the update, the phone will offer accidental input protection for the security code. The update also adds new apps to the Nokia Collection.
What would an update be without some bug fixes? We can tell you that the update to OS version 7.10.8862.144 will fix a problem that prevented Live Tiles from updating. The update actually consists of four smaller updates which together will give you all of the new features and bug fixes.
source: NokiaCare via WPCentral