These two quotes bode well:
This is a big deal to me. I'm glad they're focusing on traversal and different approaches. Stuff like that is what separates good FPS from great ones.
I didn't realize that there were that many NPCs.
I felt that was blatantly hinted at in the first demo, where the player strafes left, looks at the enemies holding the typical "entrance," and then looks up at the wall he eventually climbs over.
Still, if it's just "you can enter this area head-on, or this one other way," it's nothing but a gimmick, in my opinion. Very hard to create a real sense of openness.