Samsung is set to release the Galaxy Note 4 mobile phone on September 3rd, and a new leak from Indonesia confirms previous reports saying that this new phone will sport a 5.7" QHD Super AMOLED display.
Some reports suggested that Samsung may release two Note 4 variants, one with a regular display and one with a curved one. A senior VP at Samsung Electronics even said that the Note 4 will have a "new form factor".
My own estimate is that during their event Samsung will launch a single device, which will sport a flat QHD Super AMOLED display. This is a major launch for Samsung and they do not have the capacity to adopt a flexible OLED yet. But it's likely that they will later on release a variant of this phone with a curved OLED, maybe in a different design than the Galaxy Round, and maybe this time it will also launch globally.
A more radical device, with a flexible OLED wrapped around the edges or even a foldable display will arrive one day, but probably at 2015 at the earliest...