I feel like so long as Last of Us is well executed, in the sense that there aren't generational holdovers like invisible walls that cut off areas that look like you should be able to explore them, or issues with scripted events overlapping and interrupting each other, that it will be enough for it to get a lot of well-deserved attention. So long as it feels open enough, less like the brilliant dioramas of Uncharted and more in the direction of something that encourages exploration (even if it's just the "feel" of that freedom), I'll be incredibly happy with it.
I really hope the writing is more than just good character interactions, which is always there in Naughty Dog titles, and has something that's thought provoking in its own right, but I won't complain if it doesn't.