There will be no co-op in The Last of Us.
The Last of Us’ main campaign will not have any co-op feature, but the game will have a multiplayer-campaign, eventually. However, Naughty Dog didn’t reveal when the multiplayer feature will be released, nor what it will contain.
Creative director Neil Druckmann, stated the following: We are supporting multiplayer with The Last of Us. We’re not ready to talk about the details of how multiplayer will be implemented, however we can say that it is not co-op within the main campaign.
That’s very interesting. So either we get to play as Ellie or Joel, alternatively they might switch it up. Think Resident Evil 4 and when Ashley was separated from Leon. I think this might be a wise decision. For instance, in Resident Evil 5. Certain parts were near impossible to finish without having the co-op feature on.