Well, I thought the fact that it was the exact same demo was somewhat of a disappointment in itself, but I was quick to recover, lol; however, I'm pretty sure the game itself is not scripted, since Druckmann and Straley themselves have already provided numerous comments stating that the game can be radically different depending on the choices you make.
Plus, the two gameplay demos were similar, yes, but they were also practically identical -- meaning he played the exact same way and shot at the exact same time. With that in consideration, (Although, first of all, you've got to admit that the fact that they could play it in such a precisely similar way means that they must've rehearsed this gameplay demo over a million times...:P), it would be pretty obvious that things wouldn't play out the same way if you avoided choking the first guy, or stayed directly with stealth, etc.
However, as much as I am looking forward to this game, just in case, (as I've learned), I shall keep my Objective Skepticism helmet close by, lol. Hope for the best, expect something slightly less than that, you know? :P