Lance: Film look is indeed sort of a strange thing to try and define. On a technical level there are very specific colour responses and associated printing responses. But that’s really only half of the story, because the real arbiter of a film look is this funny plastic thing called the human brain which does all sorts of odd things. Both it and the human eye adapt over time, so the exact same thing will look different depending on a number of things such as how long you’ve been sitting in the theatre, whether or not it was sunny or cloudy outside the theatre, how dark the theatre is, and what colour the walls are, just to name a few.
So, coming back to film… well, it’s hard to say what the film look is. It’s not the exact colours that are important, but moreover film has what I call a more “organic” feel: the highlights roll off nicely, the shadows roll under nicely, there’s a strange twist in the middle of the colour response, and a curious lack of real deep blues. When running through a projector, the fact that the photosites move around from frame to frame (grain!) adds to the effect, which your brain puts together and screams “film!”
I agree digital isn't exactly like film, but it's darn close. The gap is closing rapidly. I have a very hard time telling the difference in theater between a scene shot on film and a scene shot on a digital camera. Arri's Alexa has gone a long way to minimizing the gap.