As Uncharted 4: A Thief's End's title suggests, the game will indeed be the "final chapter" of Nathan Drake's story.
Drake, who has been the protagonist of every Uncharted game to date, will not be back according to Uncharted 4 lead designer Kurt Margenau who told GameSpot "[Neil Druckmann and Bruce Straley], our directors, they have a vision [for the game]. We are fulfilling that vision and it's going to be awesome. It's Nathan Drake's final chapter, so I think fans are going to be happy."
Druckmann also spoke to GameSpot, commenting "The first three games were the set-up, and if we were to do one more, how would we top it all off? How would we bring Nathan Drake's journey to a close? Everything we're doing [with Uncharted 4] is constructed towards that; Bringing closure to a very long journey."
Considering the probability that there will be a new protagonist after Uncharted 4, it now makes sense that Sony named the forthcoming Uncharted bundle of the first three games 'the Nathan Drake Collection'.
Uncharted is a jewel in Sony's first-party crown, with the series selling 21 million copies to date and it's unlikely the series will simply finish after A Thief's End.
It's possible future Uncharteds could place players in the shoes of a younger Sully, have them play as Nathan's brother Sam, or introduce a new character altogether.
Uncharted: The Nathan Drake Collection is set for release on October 7th, while Uncharted 4: A Thief's End will launch in Spring 2016.
