Samsung is working on foldable displays for many years, as the company is looking to release a foldable phone that will be able to merge the phone and tablet markets (or possible a small phone that opens to a smartphone sized display). The company has recently accelerated its efforts, and such a phone may be released in 2017.
Foldable OLED concept (2013)
The main technology development drive is centered on the foldable OLED display itself - which is being developed for many years. According to a new report by ETNews, Samsung has decided to "test the waters" with a foldable phone that uses two different displays. This dual-screen phone will be easier to produce than a phone with a foldable OLED display. Of course the two displays, even if these are very thin-bezel ones, will still not merge to a real single display when the phone is open.
Last month Japan Display demonstrated just such a device - that uses two thin-bezel LCDs. It is likely that Samsung will opt for OLEDs, though, as these are thinner and more efficient displays. Interestingly a similar idea was reported back in 2015.
Samsung W2017
Is that story likely? Clamshell phones have been around for many years... and Samsung actually kept this form factor alive with new phones released from time to time, mostly in the Chinese market (the latest is the $3,000 W2017 android clamshell). These phones use two displays - but one on the outer side and another on the inside. The new phone reported by ETNews will have both displays on the inside.
Meh...I love OLEDs in phones but after getting my Galaxy S7 the one thing I really wish for is for Samsung to either stop with that curved display stupidity or find a way to offer hardened glass protectors that work with curved screens. Since right now there does not seem to be a single good solution for this out there. All you can get is either plastic or it only covers (the flat) part of the screen which destroys the usability.
A dual screen is way down on my priority list right now...