That sort of functionality might actually be useful and more durable that one of these daft folded screens. The only way I can see it working in this format is for the hinge to allow the halves to completely fold through 360 degrees like many of the 2-in-1 laptops. You could go a bit further and allow the screen to be on one half and a soft keyboard on the other. That is reminiscent of the old Nokia communicator.
At least with Android there are some Apps available.
I once did a proof of concept with a small sliding screen hand held from OQO that ran full XP. In the end it was connectivity that killed the use-case. We just could not get a reliable mobile connection using Edge, GPRS or whatever the very mobile earliest data protocol was.
At the time it was a pretty funky piece of hardware.