The only other portable recorder capable of doing so right now is the Odyssey 7Q from Convergent Design. Newsshooter is on the floor at Inter BEE in Tokyo, and they talked with Atomos CEO Jeromy Young:

As a reminder, here are the specs:

  • 1920x1200 IPS Touchscreen Display
  • Records 4K (3840x2160) up to 30 fps
  • Records 1080p up to 120 fps
  • ProRes and DNxHD 10-Bit, 4:2:2 Encoding
  • Uncompressed Cinema DNG Raw 4K Support
  • UHD 4K-Capable HDMI Input
  • 12G-SDI Input and Loop-Output
  • Stores to Non-proprietary Single or RAID HDDs or SSDs
  • Rec. 709 Calibrated with 3D LUT Support
  • XLR Audio LEMO Breakout Cable Included
  • Availability: December 2014
  • Price: $2,000

The screen on the Shogun is very nice, and as far as 1080p screens go, there is nothing in this price range that also doubles as a recorder, either for high-quality ProRes files or for much smaller ProRes proxies from cameras that shoot RAW internally, like Blackmagic, RED, or even ALEXA XT. 4K ProRes would be fantastic for a camera like the FS700, but we'll have to wait and see if they can implement it. If you've got an a7S, the Shogun is your best bet for recording 4K, so I'm sure many are eager to start getting much higher quality files out of that low-light monster camera. 

B&H states that the recorder will be available starting in December, so I would expect it to be in many people's hands by the end of this year. 

Atomos Shogun — B&H