Nokia has announced that the next firmware update for Lumia phones will be named Lumia Black, which is also the official name of Bittersweet Shimmer. Nokia introduced the Screen Glance (Glance Screen) feature in the Lumia Amber update, and the Lumia Black update will continue to improve upon this: adding support for background images, a new blue-green color option in addition to red for the night mode, as well as icons for lock screen notifications.
These features will all come with Lumia Black. Additionally, there's a "step counter" feature that can display the number of steps you've taken with your phone on the screen glance. The Verge reported that Nokia announced Lumia Black would be rolled out to Lumia devices within weeks, with some features arriving early next year. However, Microsoft announced that Lumia Black updates will begin rolling out early next year (temporarily assuming it was a mistake made by Microsoft).
(via The Verge)