Sony have announced that their upcoming product "Sony Sirius" or "D6503" will include 4K recording. This model is the successor of Xperia Z1 and this will run on the latest Android platform 4.2.2 or KitKat.
This 4K recording feature is to be called as Timeshift Video. That records the framerate video and apply slow motion to that.
The phone will include something Sony calls "Smart call handling," which lets you handle upcoming calls without touching the phone's screen — if you bring the phone to your ear, you'll automatically answer the call, and if you shake it, you will reject it. Finally, if you place the device face down, it will set itself to mute.