Earlier Today, Some News sites published a bunch of Screenshots and even gif images of New Google Nexus Launcher. Though they could have posted the .apk file itself!
Well, Thanks a lot to Ananda Basak for uploading Nexus Launcher Apk file. You guys can download and install the new Nexus Launcher on your Smartphones.
You can just Download the apk file from below and Install it on your Smartphone. We have tested Nexus Launcher on Android 6.0.1 Marshmallow and its working fine.
Download - Nexus Launcher
( Mirror )Download - Nexus Launcher
( Thanks Ananda Basak G+ )