According FDtimes Sony will show a new 4k motion picture camera prototype at NAB (April 9-14).
"It doesn’t have a name yet, but instead of calling it the Next CineAlta Camera, let’s give it the working title of Cine Altissima. She is not a mere 4K motion picture camera. Behind the PL mount, there’s an 8K sensor: 8768 x 2324 pixel single CMOS sensor (that’s 20.4 Megapixels) — Super35 3-perf size, 16-bit RAW output, 16:8:8."
Some additional specs: 1-72fps and 1-120fps in "High Frame Rate". The camera will have a dockable SR memory card recorder and at 24fps, 1TB memory card will record one hour of video. The camera doesn't have a name yet.
In December last year Sony announced their 4k video roadmap.