According to the Chinese tech site WPDang, the much awaited Windows Phone 7.8 OS update will be pushed to all first generation Nokia Lumia devices today starting 18:00 GMT, January 30, 2013.

WPDang claims that the WP7.8 update roll-out will cover all older devices, regardless manufacturer, region or carrier, and will be pushed in four stages (each covering 25% of the equipment). All devices will be covered in three weeks

 [Source, Via]