Samsung sent out invitations to a Galaxy Unpacked event on March 1st in Barcelona, where the company will likely unveil the next Galaxy device - the GS6.
The invitation seems to indicate a curved device - although it's not clear to me what kind of design is hinted at here. It's possible that Samsung will use a flexible OLED display curved on the edge - in a similar design to the Galaxy Note Edge shown below. According to some reports, the GS6 will sport a dual-edge display (the Note Edge is only curved on the right side).
SDC is currently producing flexible OLEDs in a 5.5-Gen line with a capacity of only 8,000 substrates per month. While the company is constructing a new 6-Gen flexible OLED fab which will increase Samsung's flexible OLED capacity dramatically - I cannot see SDC supplying a flexible OLED for the GS6. It's highly likely that Samsung will unveil two variants, one with a normal glass-based display and one with a curved flexible OLEDs, exactly as they did with the Note 4 and the Note Edge.
While curved displays are nice, what we're really looking forward from Samsung is a foldable OLED phone. Samsung is already developing these next-gen displays. In November 2014, SDC demonstrated two foldable OLED prototypes - a 5.5" (WQXGA, 2048x1526, 464 PPI) panel that folds in half and a 10" tri-foldable AMOLED (Full-HD, 218 PPI). The 10" AMOLED will enable the company to release a tablet that can be folded when not in use. But it seems too soon for such a commercial device.