What if there's a Uncharted 4 trailer which ends with a Playstation 4 logo! There must be at least on next gen game trailer there. But they'll probably end the show with Guerillas next game.
I doubt we would get a next-gen Naughty Dog trailer at the same time they are showing off their next release, it would completely take the limelight off The Last of Us.
If we get anything for next-gen I imagine it would be a short teaser rather than any sort of real trailer showing anything that actually matters, lol.