It is typically the norm that wallpapers are one the first things that get leaked prior to the launch of a new Android version. As you may already know, Android 5.0 Lollipop was built using Material Design elements. If you have been longing to get some that goodness on your phone, the Material Wallpapers app can help.
The person behind the app, HarshSinghvi, put together 30 high-res wallpapers which include the 11 official ones from Google and some that he built with Material Design in mind. You really need to try them to appreciate the work he put in. The Material Wallpapers app is free and available in the Play Store. Give it a try!