The APK comes courtesy of Antonio Luciano on Google+. The new Google Nexus launcher APK is now available for download. I’ve installed it and it’s the real deal, complete with the new slide-up app drawer and Google ‘button’ for quick search and access to Google Now.
Simply enable Unknown Sources in your Security settings, install the APK, hit home and choose Nexus Launcher. When you long press there’s a settings menu that includes a ‘Show Google app when swiping left’ option as well as options for screen rotation and app suggestions at the top of the app drawer. There’s a new widget picker too but the rumored Calendar shortcut when tapping the date up top isn’t working for me. Others have noted force closes when trying to select a new wallpaper, but flashing the zip via TWRP fixes that problem. Flashing the zip will also enable the swipe right for Google Now action.