You don’t need to have Google Nexus 5, Nexus 6, Nexus 9 and Nexus Player in order to enjoy Android M Developer Preview features. No need to flash the Android M Developer Preview image. Yes, you can also install and use Android M stuffs like launcher, clock, boot animation, wallpapers, ringtones, Play Services and stock Nexus Android M applications on your current Lollipop and KitKat devices now. We can enjoy all of these wonderful features thanks to XDA Developer, FaserF who extracted them from Android M Developer Preview ROM.
Most of these applications will work on most Android devices, including Nexus stock Android, AOSP (CyanogenMod, Omni), LG UI, Samsung TouchWiz and HTC Sense. And some might not. Therefore, just try them out one by one to find out. Download Android M Launcher, Camera, Clock, Apps, Boot Animation for Lollipop & KitKat here.