The Andromium Superbook is a Kickstarter project:
https://www.kickstarter.com/projects/an ... -laptop-f/
The Superbook is a shell, that uses DisplayLink technology, and apparently will work with just about any computer device that supports USB-OTG. On many phones it also supports simultaneous charging.
The project developers have reported that it also works with the Pi. They have posted a photo, but no details yet:
http://imgur.com/a/0dq5X
They state that the DisplayLink technology, which only transmits changes in the video, won't use up all of the USB bandwidth and it is still usable for other purposes.
I have pledged for one, at US$99 plus postage. Only 38 hours to go!