Lumia Denim was announced a few months ago in September, with launch of Lumia 735 and now its official rollout has begun. The first countries to receive Lumia Denim update is China, India and European countries and devices to be updated first are Lumia 520 and 525.
Microsoft has officially announced the list of countries receiving Lumia Denim and which are the first few devices to be updated(Click here for List), but all Lumia Windows Phone 8 and above are to receive Lumia Denim by January throughout the world.
Lumia Denim update brings several improvements in Camera App, Glance Screen, Internet Explorer and also adds Folders in Start Screen, SMS merge and forwarding and voice assistant with “Hey Cortona” voice activation. Holidays season is already in full swing and Microsoft seems to be making it more pleasant at least for few Windows Phone users.