Certainly if next gen.
If current gen, it's hard to imagine how...
There is not much to squeeze here... It would be very hard to improve on anything IMO.
It's perfectly fine for this gen and easily ready to be tweaked for next gen.
As for a sequel... Just release on either or both... I'd buy it
I'm pretty sure Naughty Dog's next game will be on the PS4 only. You know, to push people into buying the next console.
Well some companies, who made XBox 360, and PS3 games, still published PS2 versions of their games untill last year (because support for the PS2 was dropped). So I don't doubt for quite a while we'll start to see games being released for PS3/4 and 360/ONE. I'd say once 2014 ends, PS4, and ONE, are going to start getting the AAA titles.
Except there's already exclusives for PS4/One. inFAMOUS Second Son being only one(that I'm quite sad about :c)
The next possible The Last Of Us game will be much more amazing than the grafics of Part 1.
Not that the grafics are bad from Part 1 they are amazing for the playstation.
Why i know this?
Well, the next naughty dog game will be definatly not The Last Of Us 2 ...
I think we will see us for TLOU2 in 2-3 years again... and then there will be a much better engine.
much more beauty and so on.