Among the headline options that come with Android 4.4 is really a refurbished desltop and application launcher. The symbols are bigger, there's more transparency, and also the application drawer makes better utilisation of the screen property. It is also heavily integrated with Search and Google Now, although you will possibly not view it in the surface level.
Sure, there is the usual search bar widget along with a swipe left will open the entire Search application, however the integration goes much much deeper than that. While developing KitKat, Google designed a quite interesting decision: instead of graft a couple of new search UI pieces to the desltop, Google put the present home application within the trash and switched all desltop functionality to google's Search application.
Ars Technica took a closer look to Android 4.4 KitKat and found that the Google Home launcher has been sacrificed in favor of the new Google Search, which takes over the screen in a similar fashion Facebook's launcher does:
That's right, Google Search isn't just integrated into the home screen, it is the home screen. Everything you see on the home screen-the wallpaper, the icons, the widgets, and the app drawer-are all drawn by the Google Search app. "GoogleHome.apk" still exists, but it is an empty shell that forwards everything to the search app.
The difference here is that Google does it in a more subtle way than Facebook, which isn't obvious to the user and doesn't change the overall experience when it comes to visual elements.