Specifically, there is an "L Developer Preview" and also the release of Google Play Services 5.0...
The head of Android, and Chrome, Sundar Pichai unveiled the new OS elements, which includes, support for 64-bit chips, more animation support, and new login systems, as well as the new UI. Note that there is no confirmed roll-out date for the new version.
The "Material Design" UI includes support for floating screen elements, differentiating on "height" with the aim of providing a differenet dimension to the interface. We shall see how that plays out.
"We’ve been working on a new design language at Google that takes a comprehensive approach to visual, motion, and interaction design across a number of platforms and form factors, says the company. "Material design is a new aesthetic for designing apps in today’s multi-device world. The L Developer Preview brings material design to Android, with a full set of tools for your apps. The system is incredibly flexible, allowing your app to express its individual character and brand with bold colors and a variety of responsive UI patterns and themeable elements."
What else is there to expect when version 5.0 actually appears?
- Enhanced notifications ("New lockscreen notifications let you surface content, updates, and actions to users at a glance, without unlocking")
- Document-centric Recents ("Users can flip through Recents to find the specific task they want and then jump deep into your app with a single tap.")
- Project Volta for power efficientcy ("Battery Historian is a new tool that lets you visualize power events over time and understand how your app is using battery")
- BLE Peripheral Mode ("Android devices can now function in Bluetooth Low Energy (BLE) peripheral mode")
- Multi-networking ("Apps can work with the system to dynamically scan for available networks with specific capabilities and then automatically connect")
- Improved camera fucntionality ("A new camera API...your app can capture uncompressed YUV capture at full 8 megapixel resolution at 30 FPS")
- Game development support ("Support for OpenGL ES 3.1, gives you capabilities such as compute shaders, stencil textures, and texture gather for your games")
- Android Runtime (ART) ("ART offers ahead-of-time (AOT) compilation, more efficient garbage collection, and improved development and debugging features")
See also: Android 5 "L" new features and UI [PC Pro]