In early 2016 we heard reports that Samsung is aiming to introduce its first foldable phone in 2016 - earlier than the planned 2017 launch. But new reports from Korea suggest that while SDC will indeed start producing foldable OLEDs in late 2016, Samsung Electronics will release the actual device in 2017 - perhaps this will be the Galaxy S8?
The reports further says that the display will be a 5" smartphone when closed and a 7" tablet when opened. SDC and Samsung Electronics both have several technical challenges to overcome before a foldable smartphone is mass produced - but the companies believe they will manage to solve those challenges and achieve mass production before the end of the year.
Samsung indeed seems to be quite close to actual foldable-display commercialization and demonstrated two foldable OLED prototypes towards the end of 2014 - a 5.5" (WQXGA, 2048x1526, 464 PPI) panel that folds in half and a 10" tri-foldable AMOLED (Full-HD, 218 PPI). The company also reportedly recently chose its substrate of choice: Solip Technology's hybrid glass-plastic material.
Samsung's original plan was to release a foldable phone in 2015, but this obviously will not happen. Market research company IHS actually expects Samsung to release the first foldable phone in early 2016. The OLED Association also expects Samsung to show a foldable smartphone, but only as a prototype or "near-production" model.