Google Experience Launcher (GEL) and Google Search 3.1.8 (massive update) are now available for download and work well on any Android 4.1+ device. I don’t know if or when these will hit Google Play since they are just now being rolled out to the Nexus 5 with Android 4.4 (KitKat). So basically, this is the Nexus 5 launcher/experience.
You can use GEL optionally as a replacement for your normal home launcher. Your call.
The only minuses I’ve seen with GEL are 1) if you have two screens of icons/widgets and you move everything to the second screen (leaving nothing on the first screen), all of the icons and widgets will automatically move to the first screen and 2) no pinch zooming of desktops (stock Android has never been able to do this).