I know we have practicality no information involving Uncharted 4's plot, but when I look at the whole series and The Last of Us, I think there's a possibly that there could be one.
Spoiler free, if you're wondering. 
1. If you don't know, there's an Easter Egg in Uncharted 3 that references The Last of Us: http://www.ign.com/articles/2013/05/30/uncharted-3s-the-last-of-us-easter-egg-left-in-by-mistake
And there's also an Uncharted 3 Easter Egg in The Last of Us: http://www.youtube.com/watch?v=PGIO5a4P4zU
So, that (Sort of...) confirms that the games are in the same universe.
2. We all probably assumed (Or didn't think of) that all the Uncharted games take place in the year they came out (Which is probably true, since Sully referenced something in Uncharted 1 ((Which released in 2007)) in Uncharted 3 ((Which released in 2011)) and said it was "4 years ago".)
So, since The Last of Us is (Well, might be... 
) in the same universe as Uncharted, wouldn't it be the same?
The timeline would be like this:
2007 - Uncharted 1
2009 - Uncharted 2
2011 - Uncharted 3
2013 - The Last of Us (First part of the game. The second part would be 2033 and eventually 2034)
2015 - Uncharted 4
I bolded the last two because, if The Last of Us starts before Uncharted 4, wouldn't that mean that a large portion of the population are Infected by the time Uncharted 4 happens?
It's possible that there could be Infected in the game, obviously, but since they're a widespread problem, wouldn't they be everywhere, (IMO) ruining the Uncharted formula, and (Again, IMO) be really gimmicky at the same time? I doubt Naughty Dog would do that.
Tell me your opinions! Do you agree with me? Or do you think I'll have a really bad hangover tomorrow? Probably the latter...
