After reading expert magazins, I believe Samsung switched to the Android Desktop Software Foundation. Unfortunately a bit too early in my opinion. This is clearly "work in progress".
the benefit is a standardized platform over all Android Smartphones and tablets. This makes it a lot more attractive for app development to adapt their software for desktop specific behavior like resizable window, keyboard control (hopefully also mouse), etc.
This could be a final breakthrough. Enterprises could save costs and give employees just a phone which covers 60-80% of mainstream work. the rest could be done on virtual Windows PC that displays on Android.
If that fails however, desktop mode will be dead forever.