Voice actor Nolan North has been spilling all the beans this week. At last week's Metrocon event he gave an hour-long talk on how he got into the industry, as well as answering questions from fans.
Amid anecdotes of riding horseback into the ancient city of Petra and stories about how every guard in Uncharted that walks with a limp is his work, North revealed that when Amy Hennig left Naughty Dog last year the studio scrapped eight months of work on Uncharted 4 to start over.
Later in the talk someone in the audience asks North if he's any more work scheduled with Naughty Dog. "Not yet," he answers, "I know they're doing The Last of Us 2."
Naughty Dog has never confirmed a sequel to The Last of Us. Creative director Neil Druckmann said in a Reddit AMA that there was a "50/50" chance of a sequel being made. And, in a comment to Eurogamer, Druckmann admitted the team had brainstormed ideas for a sequel. But North suggests the team is already at work on The Last of Us 2.
Of course, this isn't an official confirmation but North does have a good relationship with the studio and he may well have heard things.
I've contacted Naughty Dog for comment.
If you've got the time (the video's a little over an hour), I'd recommend watching North's full Metrocon talk. I finished it up this morning and it's got me excited to play the Uncharted games all over again.