Microsoft is about to push out Lumia Denim to more models globally (UPDATE: Denim is coming to these models)
The update includes the ability to activate personal assistant Cortana by saying "Hey Cortana." With the Lumia Denim update, you can move apps into a folder on your Start Screen. Word Flow allows you to swipe your fingers across the keyboard to type, similar to Swype. After installing the update, you will have the choice of adding weather data to your Glance screen, or viewing some of your fitness data. And Internet Explorer takes you to mobile websites faster than before.
Certain updates to the camera are available just for the Nokia Lumia 930, Nokia Lumia Icon and the Nokia Lumia 1520. Among those changes, you will be able to take picture after picture after picture just milliseconds apart. In addition, booting up the camera is faster than ever. With Rich Capture, three exposures of a single picture are melded together to give you a more realistic looking photo, and Moment Capture lets you shoot video in 4K.
In the U.S., Lumia Denim has already been received by the Nokia Lumia 928 and the Nokia Lumia 822. Other models in the states should start receiving it once the carriers finish their tests. Overseas Windows Phone users can also expect to see a wider rollout of Lumia Denim to more Lumia handsets.
source: Microsoft via Engadget
UPDATE: The Lumia models receiving the Lumia Denim update worldwide with this wave of updates are the Nokia Lumia 520, Nokia Lumia 620, Nokia Lumia 625, Nokia Lumia 920 and the Nokia Lumia 1020. More Lumia models will receive the update in the next wave of updates.